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

Tutors Answer Your Questions about Geometry proofs (FREE)

Question 254404: how can i prove that two lines are equal to each other if the are on the same line of a rectangle, like A and B in each corner of the line and c in the middle? Meaning AC=BC on a rectangle
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Question 254420: Draw a horizontal line l and a point P not on l. Construct a line m through P perpendicular to l. Draw a point Q not on m or l. Construct a line n though Q perpendicular to m. What postulate or theorem guarantees that the lines l and n are parallel?

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Question 254624: draw line t and line m so they are perpendicular, and give the measure of all anglges?
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Question 254788: Given: parallelogram HIJK and triangle HOL is congruent to triangle JOI. Prove:HIJK is a rhombus. how do i solve this?
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Question 254796: What is the two column proof for this question:Write a two-column proof that shows Pine avenue is parallel to Maple avenue. Pine avenues coordinates are (0,1)(5,2) and Maple avenue is (11,-10)(1,12)
Help please.
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Question 254772: triangle xkf equalilateral xj bisect angle x.

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Question 254834: how would you design a circuit for ahall light that has switches at both ends of hall such that the light can be turned on or off from either switch. I have to use this problem for this question Electrical circuits are designed using truth tables.circuit consists of switches. And wired in series as p^q. two switches wired in parallel can be use as p v q. Can you show me how to do this problem using the truth table
Click here to see answer by richwmiller(9143)

Question 254878: I cant understand proofs as hard as I try.I either put the wrong reasons and statements or cant find any statments or reasons to put.I really want to know how I can better understand proofs.My teacher is no help.So please HELP!! :(
Click here to see answer by richwmiller(9143)

Question 254991: Given:
E is the midpoint of BC
AB is parallel to CD
Prove: AB is congruent to CD

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Question 255007: GIVEN: AB is congruent to AD
FC is perpendicular to BD
PROVE: triangle AEF is isosceles
F
/ |
/ |
A. |
/ \ |
/ \ |
/ | E
/ | \
/ | \
/ | \
B ------------C-----D
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Question 255084: in a quadrilateral ABCD, ray AC bisects angle DAB and ray CA bisects angle DCB. prove angle B congruent to angle D. please help me im having trouble drawing what the picture would look like
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Question 255370: I need help with my geometery proofs.
Given: BF is parrallel to CD
Prove: AB/AC=BF/CD (ab over ac is equal to bf over cd)
This is a 2 column proof.
Picture: One little triangle is inside of a bigger triangle. Both triangles share the same vertex angle.
Statements:
1. BF is parrallel to CD.
2. Angle 1 is congruent to Angle C, Angle 3 is congruent to Angle C.
3. Angle A is congruent to Angle A.
4. Triangle ABF is similar to Triangle ACD.
5. AB/AC=BF/CD
Reasons:
1. Givens
2. Corresponding angles are congruent.
3. Congruence of angles is reflexsive.
4. Angle Angle similarity
5. Def of similar Angles.
Thanks so much!
Click here to see answer by richwmiller(9143)

Question 255974: find the area of an equilateral triangle with a perimeter of 9.
Click here to see answer by manas(5)

Question 255998: given:
angle 1 is congruent to angle 2
prove:
tiangle JOE is isosceles

(please really need help.. i'm bad in geometry..)
Click here to see answer by Theo(3464)

Question 256042: hiya
I wanted you to tell me the proof that altitudes on a triangle are congruent using Ceva's theorm. But i nned to know the proof using trigonmetry.
the diagram i was given was of a triangle ABC and a line that is perpendiular to the line BC (at point A')and hits vertex A. also i have an angle at A*B*A' 'b'.
Could you help me please? thanQ for looking
Click here to see answer by solver91311(16897)

Question 256056: Prove that if 3x-2=x-8
Given: 3x-2=x-8
Prove:x=-3
Click here to see answer by drk(1908)

Question 256584: Prove: If a/b, then a/(bc)
This is a proof that you would have to prove through steps. First give the steps then the reason. For example, Reflexive property, Definition of Divides and others. Please Explain THOROUGHLY!!!!
Click here to see answer by richwmiller(9143)

Question 256610: Suppose J is between H and K. Use the segment addition postulate to solve for x. Then find the length of each segment.
The problem is: HJ=3(x+2)
JK=3x-4
KH=44
Click here to see answer by palanisamy(496)

Question 256663: Given: x(x-2)=(x+4)(x+6)
Prove: x=-2
Write steps and justify property.
Please and thank you very much
Click here to see answer by stanbon(57387)

Question 256982: In segment ABCD,(which is shaped like a rhombus) angle A is greater than angle D. AB is greater than DC. Prove that AB is not parallel to DC.
I have tried many ways to answer this problem, and my most reasonable solution was the hinge theorem since we have recently learned this. I have to write an indirect proof, and I dont even know how to solve this problem. Oh, and on the rhombus, angle A is in the top left and angle D is in the bottom right. And B is on the top right and C is on the bottom left. There is a line going from B to C, dividing the rhombus into two triangles. Please help!
Click here to see answer by MRperkins(300)

Question 256974: The odds against Jason being promoted are 4:11. Find the odds in favor of Jason being promoted. Find the probability that Jason will be promoted.
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Question 257449: A class has 12 females and 11 males. If two different students are selected at random to go to the board, what is the probability that both students will be males?
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Question 257452: For the scores 60, 49, 58, 45, 55, 62, 49 find the following:
a.) mean - 54
b.) median - 55
c.) mode - 49
d.) range- 9
e.) interquartile range- 11
f.) standard deviation-
(that i am stuck on) I hope I did the rest correct. Could you please explain how to get that standard deviation?
Click here to see answer by Edwin McCravy(8909)

Question 257490: Given: AB and CD bisects each other at M
Prove: AD is parallel to BC
Picture: Two triangles connecting to get, kind of like a bow tie.
Click here to see answer by drk(1908)

Question 257492: Given CD is perpendicular to AB
AD is congruent to BD
Prove: A is congruent to D
Picture: One triangle with a perpendicular bisector.
Click here to see answer by richwmiller(9143)

Question 257494: Given: Triangle ABC
Prove: m<4= m<1 + m<2
Picture: A triangle with line, CD, connected to it. A is m<1, B is m<2, C is m<3, and m<4 are vertical angles to m<3
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Question 257477: description of postulate 3

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Question 257765: given: 4x+8=2
prove:=-2
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Question 257760: given: 4x+6 over 2 = 9
prove: x=3
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Question 257864: what is the property of equality if AC = AB and AC = BD, then BD = AB + BC
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Question 258010: Given AD = AE, ∠ADE = ∠C Prove: DE ∥ BC

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Question 258010: Given AD = AE, ∠ADE = ∠C Prove: DE ∥ BC

Click here to see answer by Edwin McCravy(8909)

Question 258115: The Fahrenheit temperature readings on the first fifteen April mornings in Stormville, New York, are shown below in List A; the readings for the last fifteen days of April are shown in list B.
List A: 41,58,61,54,49,46,52,58,67,43,47,60,52,58,48
List B: 44,59,66,62,55,44,49,62,61,59,54,57,58,63,60
Construct a back to back stem and leaf plot for these two sets of data.
What conclusion(s)can you make about the temperatures in April based on the plot?
Click here to see answer by drk(1908)

Question 258167: Given:angleB is congruent to angleD
Line BC is parallel to line AD
Prove:Line DC is congruent to LineAB
Click here to see answer by richwmiller(9143)

Question 258555: What is the difference between the SSS, ASA, and SAS postulates?
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Question 259145: How do you prove a kite is a rhombus?
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Question 259497: I have a question about finding midpoints of a line segments when given the end points example: {-4/3,12/7},{7/4,2}
Click here to see answer by checkley77(12569)

Question 259829: Explain how to construct a line parallel to a given line. Tell which theorem or postulate you use.

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Question 259990: Explain why you cannot use postulate AAA to prove two triangles congruent
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Question 259845: I do not understand proofs or in what order to put the statements according to the rectangle. But here is a question that I need help on.
(Rectangle)ABCD is a rectangle. Line AC and Line BD are diagonals that intersect at a point, E. Prove that Triangle AEB is congruent to Triangle DEC.
Click here to see answer by mananth(12270)

Question 260453: Given: A (4,3), B (8,3), C (9,10), and D (5,10) are vertices of a quadrilateral. Is quadrilateral ABCD a parallelogram? Use mathmatics to justify your answer. (graphing is not acceptable) .... I need an example or this answer cause im very confused....Thank you
Click here to see answer by jim_thompson5910(28598)

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