Questions on Geometry: Proofs in Geometry answered by real tutors!

Tutors Answer Your Questions about Geometry proofs (FREE)

Question 626389: complete the following proof related to the figure below.
the figure is a triangle with a line down the middle, the top is labeled T, angle on the right is S, angle on the left is R and the bottom of the segment that goes through the middle is labeled Q.
Given: segment TQ bisects angles RTS, angle R=angles S Prove: segment TQ is perpendicular segment RS
Click here to see answer by solver91311(24713)

Question 626397: prove that if the two sides of an angle are perpendicular to the sides of another angle , then the angles are either equal or supplementary.
Click here to see answer by Edwin McCravy(20054)

Question 626471: I have a diagram of an isosceles triangle The verticals A and B are shown to be congruent. The only information that is given is the angel of A It is 96 deg. The practice question asks for the values of the angles for B and C.
B/\
/ \
/ \
96 /______\C
How can I find B and C?
I am in 10th grade trying to get ready for the next school year. Sorry the triangle did not come out to well on the email.
Click here to see answer by solver91311(24713)

Question 627052: PA IS TANGENT TO THE CIRCLE WITH CENTER O, PROVE APB ~ CPA
Click here to see answer by solver91311(24713)

Question 627052: PA IS TANGENT TO THE CIRCLE WITH CENTER O, PROVE APB ~ CPA
Click here to see answer by Alan3354(69443)

Question 626598: Given: Angle RXW is congruent to angle YXS.
Prove: Angel 4 is congruent to angle 1.
Click here to see answer by richard1234(7193)

Question 627361: Good afternoon,
Determine the truth value of the following statements:
The Mona Lisa is a famous painting and all even numbers are divisible by 2.
a)True
b)False
Click here to see answer by jim_thompson5910(35256)

Question 627415: what is a valid conclusion to <1 AND <2 ARE SUPPLEMENTRY
Click here to see answer by jim_thompson5910(35256)

Question 627489: Hello, can you please help me prove that all four angles of a rectangle are right angles.
Thank you :)
Click here to see answer by richard1234(7193)

Question 627805: 25 cent - a quarter is 3/4 inch in diameter. When placed 7 feet from eye, it blocks the disc of moon. Diameter of the moon is 2160 miles. How far is the moon from the earth?
Click here to see answer by ankor@dixie-net.com(22740)

Question 628851: I have three parallel lines, so I know I have a plane. What definitions or postulates from Lesson 1 would I use to prove that? Use at least three definitions, and explain how they work together to prove that there is a plane.
Click here to see answer by Alan3354(69443)

Question 628893: A student states that the lengths of 3, 2, and 1 can be the sides of a triangle because 3 plus 2 is greater than 1. Determine if the student is correct. Explain your reasoning.
Click here to see answer by Edwin McCravy(20054)

Question 629457: m<1= m<2
Click here to see answer by Edwin McCravy(20054)

Question 629645: how can i prove opposite angels are congruent in a parallelogram. Please draw a proof and diagram of it thank you
Click here to see answer by Edwin McCravy(20054)

Question 629736: http://i.imgur.com/Ux3BT.png - this one i need the first questioned answers i know its wrong.
http://i.imgur.com/RBDzM.png
16. Reason 6 of theorem 2.7 should be
1. given
2. addition property
3. definition of congruent angles.
4. definition of suppplements.
19. Statement 5 of Theorem 2.7 should be
1. angle B (equal to or congruent) angle D
2. mA + mB (equal to or congruent) mC + mD (after the M's should have the angle sign)
3. mA (equal to or congruent) mC
4. mB (equal to or congruent) mD
Then 8-11 (seems easier this way)
http://i.imgur.com/Q8ywN.png
Click here to see answer by solver91311(24713)

Question 630047: If line segment AB = 12 feet, what is the length of line segment AC?
Click here to see answer by Alan3354(69443)

Question 630690: This is more a calculus Proof Question, but I wasn't sure what section to put that under :)
cos(x)/(sec(x)-tan(x))=1+sin(x)
I got to cos(x)/(1-sin(x)/cos(x)=1+sin(x)
Thanks for your help!
Click here to see answer by Alan3354(69443)

Question 630966: Given ΔABC, Segment AD bisects ∠BAC, Segment AE congruent to segment ED. I need help proving: AE/AC=BD/BC.

If anyone can please explain and help me solve this. I would greatly appreciate it! I cannot figure this out, even after looking through my book or MML (My Math Lab)
Click here to see answer by mananth(16946)

Question 632046: can you please show to me the proof of the sum of the exterior angles of any polygons which is equal to 720 degrees..thank you.
Click here to see answer by Theo(13342)

Question 632406: Starting from the sum of exterior angles prove that in a regular polygon of n sides, the measure of each interior angle is n-2*180/n.
Click here to see answer by solver91311(24713)

Question 636251: Given A = {1,2,3,4,5,6}, B = {1,2}, and C = {6, 7}. Evaluate each set
a) A ∩ B
b) A U C
c) B U C
d) (A U B) ∩ C
e) A U (B U C)
f) (A ∩ B) ∩ C
g) (A ∩ B) U C
Click here to see answer by jim_thompson5910(35256)

Question 636250: An electronics store surveyed every 11th customer who came into the store for a week.
Of the 375 people who responded,

181 people watched movies on VHS tapes.
245 people watched movies on DVDs.
66 people watched movies both on VHS tapes and DVDs.

Create a Venn diagram to reflect the above data, label your diagram clearly and submit to the Dropbox. Use your diagram to answer the following questions here.

i. Of those surveyed, how many watched only VHS tapes?
ii. Of those surveyed, how many watched only DVDs?
iii. Of those surveyed, how many watched VHS tapes or DVDs, but not both?
iv. Of those surveyed, how many watched VHS tapes or DVDs, or both?
Click here to see answer by ewatrrr(24785)

Question 636557: I need the steps to working out this proof problem.
GIVEN: LINE PA IS TANGENT TO THE CIRCLE WITH CENTER O; PROVE: TRIANGLE APB ~ TRIANGLE CPA
Click here to see answer by Edwin McCravy(20054)

Question 636868: determine whether the argument is valid or invalid. You may compare the argument to a standard form, or use a truth table.
V → W
W
________
.
. . V
Click here to see answer by jim_thompson5910(35256)

Question 637079: Write a negation of the statement.
Some athletes are musicians.

a) All athletes are not musicians.
b) Some athletes are not musicians.
c) All athletes are musicians.
d) No athletes are musicians.
Click here to see answer by MathLover1(20849)

Question 637081: Construct a truth table for q --> ~p
Click here to see answer by MathLover1(20849)

Question 637224: How would I solve this proof?
(The picture shows an angle with A being the vertex, B being the bottom ray, and C being the top ray.)
GIVEN: line AB is congruent to line DE, line AC is congruent to line DF, and line BC is congruent to line EF
PROVE: angle D is congruent to angle A
I understand that angle D is congruent to angle A, but I have trouble figuring out which theorems and postulates to use to prove it and how a one statement leads to the next (figuring out how I should order my statements).
Thank you so much for your help!
Click here to see answer by solver91311(24713)

Question 637226: Identify which argument is invalid.

If I sing in the shower, then I will not be overheard while singing.
I did not sing in the shower.
Therefore, I was overheard while singing.

If Sally is on vacation, then Tom is at work.
Sally is on vacation.
Therefore, Tom is at work.

Either Sally is on vacation or Tom is at work.
Sally is not on vacation.
Therefore, Tom is at work.

If Jan gets lost, she will need a map.
Jan got lost.
Therefore, Jan needs a map.

If I shower in the morning, then I do not smell bad.
I smell bad.
Therefore, I did not shower in the morning.
Click here to see answer by solver91311(24713)

Question 638260: 11. Form the inverse: If I do not change my car�s oil, then my car will have engine trouble
If my car does not have engine trouble, then I changed my car�s oil.
If my car has engine trouble, then I changed my car�s oil.
If my car does not have engine trouble, then I did not change my car�s oil.
If my car has engine trouble, then I did not change my car�s oil.
If I change my car�s oil, then my car will not have engine trouble.

Click here to see answer by MathLover1(20849)

Question 639106: What reason would you use to prove that segment AB is congruent to segment AD and segment BC is congruent to segment DC?
Click here to see answer by solver91311(24713)

Question 639113: Good day! I am not very familiar with this type of math problem, can you please help me answer this? thank you!
C is the midpoint of line segment AB. Show that AC= 1/2 AB and CB = 1/2 AB. Supply steps and reasons for this problem.
Click here to see answer by solver91311(24713)

Question 639376: Given: Triangle ABC, AD bisects
Click here to see answer by asuar010(338)

Question 639489: the bisector of a vertical angle of an isosceles trangle is a perpendicular bisector of base(teaching vedio)
Click here to see answer by MathLover1(20849)

Question 639515: Good day! can you please help me with this math problem?
In the figure, line segment DE is congruent to line segment GH, line segment EF is congruent to line segment FG and line segment FG is congruent to line segment HI. Show that line segment DF is congruent to line segment GI.
_________________________________________________
D E F G H I
Thanks for your help!
Click here to see answer by vleith(2983)

Question 639829: find the exact value for the trigonometric expression?
tan(-pi/12)
HELP!
TY!
Click here to see answer by lwsshak3(11628)

Question 639895: if one angle of a triangle is greater than the sum of the other two, show that the triangle is obtuse angle
Click here to see answer by Edwin McCravy(20054)

Question 640286: Look at the figure shown below.

A student made the table below to show the steps to prove that DC is equal to EC.
Statements Justifications
AC = BC
Given
m∡EAC = m∡DBC
Given
m∡ACD = m∡BCE
Given
m∡ACE = m∡ACD + m∡DCE
Angle Addition Postulate
m∡BCD = m∡BCE + m∡DCE
Angle Addition Postulate
m∡BCD = m∡ACD + m∡DCE
Substitution

DBC ≅ EAC
ASA postulate
DC = EC
CPCTC

A. Provide the missing statement and justification in the proof.
B. Using complete sentences, explain why the proof would not work without the missing step.
Click here to see answer by solver91311(24713)

Question 640484: 1. name two different ways to continue each pattern
~a,b,c....z
~a,z,b...
2.seven people meet and shake hands with one another
~using inductive reasoning write a formula for the number of handshakes if the number of people is n.
3.the fibonacci sequqnce consists of the pattern 1,1,2,3,5,8,13...
~what is the ninth term in the pattern?
~using a calculator look at the succesive ratios of one term to the next.make a conjecture.
~list the first eight terms of the sequence formed by finding the differences of succesive terms in the fibonacci sequence.
Click here to see answer by solver91311(24713)

Question 641832: how to construct a rhombus when diagnol AC=5.6cm and BD=6.5cm IS GIVEN
Click here to see answer by Edwin McCravy(20054)

Question 642658: The question is:
Can you think of any way to prove from Euclid's postulates that for every line l
(a) There exists a point lying on l?
(b) There exists a point not lying on l?
I'm thinking it has something to do with Euclid's parallel postulate, but I'm not sure. I have never written proofs before, so I am just having a difficult time trying to formulate this properly. Any help would be appreciated. Thank you!
Click here to see answer by jim_thompson5910(35256)

Question 643021: Name two different ways to continue this patter. 1,1,2
Click here to see answer by unlockmath(1688)

Question 643016: I need help solving this proof,
PQ 5 RS. Prove PR 5 QS ____________________
P Q R S
Professor gave us this much
1.PQ=RS given
2.QR=QR Reflexive property
3.
4.
5.PR=QS
We are to do 3,4,5 and give reason, I have no clue how to do this. Help!
Click here to see answer by solver91311(24713)

Question 644444: what is the largest number of different regions into which the plane can be divided by n lines?
Click here to see answer by stanbon(75887)

Question 646113:
m∠RST = m∠TSV = m∠RSV = 49� Find x and m∠TSV

Click here to see answer by Edwin McCravy(20054)

Older solutions: 1..45, 46..90, 91..135, 136..180, 181..225, 226..270, 271..315, 316..360, 361..405, 406..450, 451..495, 496..540, 541..585, 586..630, 631..675, 676..720, 721..765, 766..810, 811..855, 856..900, 901..945, 946..990, 991..1035, 1036..1080, 1081..1125, 1126..1170, 1171..1215, 1216..1260, 1261..1305, 1306..1350, 1351..1395, 1396..1440, 1441..1485, 1486..1530, 1531..1575, 1576..1620, 1621..1665, 1666..1710, 1711..1755, 1756..1800, 1801..1845, 1846..1890, 1891..1935, 1936..1980, 1981..2025, 2026..2070, 2071..2115, 2116..2160, 2161..2205, 2206..2250, 2251..2295, 2296..2340, 2341..2385, 2386..2430, 2431..2475, 2476..2520, 2521..2565, 2566..2610, 2611..2655, 2656..2700, 2701..2745, 2746..2790, 2791..2835, 2836..2880, 2881..2925, 2926..2970, 2971..3015, 3016..3060, 3061..3105, 3106..3150, 3151..3195, 3196..3240, 3241..3285, 3286..3330, 3331..3375, 3376..3420, 3421..3465, 3466..3510, 3511..3555, 3556..3600, 3601..3645, 3646..3690