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

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Question 119616: I have been in geometry for three days and my teacher has given us one example and i just don't know how to even start to do them. we don't even have a text book. if you could help me i would really appreciate it. the problem is Give a line segment AD with points B and C between A and D. If AB=CD, then AC=BD.
Click here to see answer by josmiceli(19441)

Question 120416: I was wondering if you could go over flow proofs, i dont understand wher to start differnt points of the proof.
Thanks
Click here to see answer by Kesha Lover(1)

Question 121658: find the coordinates of the midpoint of each side.

A(3,6) B(-20) C(3,1)
midpoint of AC?
midpoint of AB?
midpoint of BC?
Click here to see answer by checkley71(8403)

Question 122081: How can you prove the converse of the diagonals of a rhombus are perpendicular.
Click here to see answer by Edwin McCravy(20054)

Question 122572: Okay i have no idea how to do this:
Given: RECT is a rectangle.
RA = 43x
AC = 214x-742
Find: The length of ET to the nearest tenth
they have a picture of the rectangle but i dont know how to put it on here.
Click here to see answer by checkley71(8403)

Question 122803: Given: Quadrilateral ABCD; Angle A is conguent to Angle C; Angle B is congruent to Angle D
Prove: Quadrilateral ABCD is a Parallelogram.
Click here to see answer by Edwin McCravy(20054)

Question 123109: If given GJKM is a rhombus, OJ is perpendicular to GM, MH is congruent to JO then conclude that MH is congruent to JO.
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Question 123775: State whether this is true or false and explain your answer.
A line may bisect a segment, but a segment may not bisect a line.
Click here to see answer by stanbon(75887)

Question 123774: State whether each statement is true or false and explain your answer.
1. There is exactly one point L on line MC such that ML=3.
2. There is exactly one point L on line MC such that ML =1/2MC
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Question 123804: (given) triangle ABC is isosceles; line CD is the altitude to base line AB
(to proove) line CD bisects angle ACB
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Question 124281: I was asked to do a proof by math induction for the formula of diagnols in a polygon. The formula for diagnols in a polygon is n(n-3)/2. N is the number of sides in any given polygon. The basis for the proof is n=3. For the basis step, I am asked to show how the generalization is true for n=3. I must show the induction hypothesis for n=k. To complete the proof by math induction, I must show that what is true for k is also true for k+1. I am asked to show the steps and leave it in simplified form. I am also asked to show the algebra that demonstrates how what is true for k is also true for k+1.
Click here to see answer by stanbon(75887)

Question 124845: What is the locus of points in the plane of an angle that are equidistant from the sides of the angle?
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Question 124847: What is the locus of points in space that are equidistant from two parallel planes?
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Question 127556: Prove the following statement: If a triangle has one obtuse angle, then the other two angles are acute.
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Question 129130: In a parallelogram ABCD,the bisector of angle A also bisects BC at X.Prove that AD = 2AB
Click here to see answer by Edwin McCravy(20054)

Question 129285: When you find the area of a square what type of units do you do?
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Question 129774: Triangle ABC is not isoceles. Prove that altitude BD would not bisect AC.
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Question 130666: degrees in a six sided convex polygon
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Question 131623: On page 336
Discover and prove a theorem about two lines tangent to a circle at the endpoints of a diameter.
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Question 132369: show that median devides a triangle in two equal parts?

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Question 132796: Given: angle 1 and angle 2 form a linear pair
angle 2 + angle 3 + angle 4 = 180
Prove: angle 1 = angle 3 and angle4
Click here to see answer by solver91311(24713)

Question 133018: How do you solve problems in proofs in general. My daughter has a huge test tomorrow and I am trying to find a step by step approach to show her how to do any problem. Is there one avail with examples? Hopefully it will be something that would make sense to me and I could try to help explain to her? Chapter 8, page 444, problem #9 would be a problem example that we would like to see help with.
thank you

Click here to see answer by vleith(2983)

Question 133453: Complete the proof
(a exponent3 + b exponent 3)*(a+b)=a exponent2 - ab+b exponent 2
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Question 133604: if angle A and angle B are complementry, and angle A=3x+4 and angle B=5x+6, find x.
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Question 133605: each base angle of an isosceles triangle has a measure that is 20 more than three times the meausre of the vertex angle. find the meausre of the vertex angle
Click here to see answer by stanbon(75887)

Question 133603:
if angle A and angle B are complementry, and angle A=3x+4 and angle B=5x+6, find x.
Click here to see answer by checkley71(8403)

Question 133602: B is the midpoint of segment AC. if BC=2x-15 and AC=x+9, find x
Click here to see answer by stanbon(75887)

Question 133602: B is the midpoint of segment AC. if BC=2x-15 and AC=x+9, find x
Click here to see answer by checkley71(8403)

Question 133828: PROVE: ST is perpendicular to SY.
GIVENS: Angle T is Congruent to Angle Y;
Angle 1 is Congruent to Angle 2;
PQ is Perpendicular to SY

PLEASE PLEASE HELP!
Click here to see answer by Edwin McCravy(20054)

Question 134737: Describe each locus of points. In a plane, the locus of points 4 cm from the center of a circle whose radius is 5cm.
Click here to see answer by vleith(2983)

Question 134749: Given a segment AB, construct and label the locus of points at a distant AB from point A and B.
Click here to see answer by stanbon(75887)

Question 134760: Please Help With This Proof!
GIVEN: Diagram as shown

PROVE: meas. angle 2 + meas. angle 3= meas. angle DCB + meas. angle 4
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Question 138759: how do you prove the property that || is transitive.
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Question 139687: ) Use the fact that every point on the perpendicular bisector of a line segment is equally distant from the endpoints of the segment to find the center of the following rotation.

I can't get the picture to come up. I figured out how to show it w/ a compass and straight edge but cannot figure out how to explain I know it's true that rotating ABC to A'B'C' can happen when you take segment A to A' and create the perpendicular bisector do the same for b and c and where all 3 bisectors intersect is the center. Why?
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Question 140888: I would appreciate it if you could solve this problem and how.
http://img341.imageshack.us/my.php?image=geometryquestion3uj1.jpg
Click here to see answer by scott8148(6628)

Question 140898: I would appreciate help with this problem. Thank you!
http://img115.imageshack.us/my.php?image=geometryquestion1pw7.jpg
Click here to see answer by scott8148(6628)

Question 141196: Help please,
In what type quadrilateral are the diagonals NOT always congruent to each other.
I think it is a trapezoid. Is this correct?

What is always true of the diagonals of a parallelogram?
I think they bisect each other and separate it into two congruent triangles.
Can you tell me if that is the right answer?
Click here to see answer by stanbon(75887)

Question 142852: find the area of an equilateral triangle with one side measuring 20cm
Click here to see answer by psbhowmick(878)

Question 143178: parallelogram abcd is not a rectangle the points of a b c and d are (-2,2) (6,5) (4,0) (-4,-3) prove that paralleogram is not a rectangle
Click here to see answer by vleith(2983)

Question 143266: we just started coordinate geometry proofs with slope, midpoint, and distance. i have the formulas for all three but i don't understand how to apply the formula to a problem.
ex) Given Points: A(2,-7) B(-3,-5) C(1,-7) D(6,-9).
1. Are lines AB and CD parallel? Are they perpendicular?
2. What is the midpoint of lines AB and CD? Do they bisect eachother? Why or why not?
3. What is the length of line AB and CD? Are they congruent?
I know this is a long problem but i don't just want the answer, i really need help understanding it all so if someone could explain it i'd appreciate that. thank youu
Click here to see answer by solver91311(24713)

Question 143397: givin am+cn
Mb=Nd
Prove ab+cd
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Question 144282: Given: angle AOC and angle COB are a linear pair.
Prove: angle AOC and angle COB are a supplementary.
Do i just need to say that they are supplementary because they are linear pairs? Does that mean the same thing?
Click here to see answer by solver91311(24713)

Question 144172: Given: triangle ABC A(-1,2) B(7,0) C(1,-6) and a point D(4,-3) on segment BC
Prove: segment AD is the perpendicular bisector of segment BC
Click here to see answer by Edwin McCravy(20054)

Question 144417: Given: A(1,6), B(7,9), C(13,6), D(3,1).
Prove: ABCD is a trapazoid
Click here to see answer by shahid(44)

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