1. ## Interesting Geometry Problem

Can anybody get this Geo Quiz,

Hint:

You need to add some lines.

2. Is ABCD a square or just a parallelogram?

3. ## Square indeed

Sorry, Yes it is a square.

4. Here are all the relationships. Some are redundant.

F = J
G = N
M = K
S = P
R = Q

F + H + J = 180
G + M + S = 180
K + N + P = 180
Q + R + T = 180

H + K + M + T = 360

F + G = 90
J + N = 90
R + S = 90
P + Q = 90

5. Cool but could you explain how you solved for angles M K and T.
You are not allowed to use Trig. sorry I didn't mention that earlier.

6. When you draw that (green) line, with the properties of a square and an isosceles triangle, you created another isosceles triangle down there. The left triangle and the right triangle also become congruent. No trig is involved. This problem can be solved completely linearly.

7. I still don't understand how you solved either angle M or angle T.

Once I understand your method I'll show you the way i did it.

Bob

8. Honestly, I did not solve for any particular angles. I formed a 12-dimensional matrix with overdetermined equations, and performed gaussian elimination on it.

9. Originally Posted by Bobby Bob
Can anybody get this Geo Quiz,

Hint:

You need to add some lines.
Proof.
If <ECD was not 60 then <BAE could not be 15.

PS
the other guy is wrong...

OK,

Paul and Prof,

Could you both post your work on how to solve this problem so that we can evaluate them both.

Bob

11. Prof is right.

12. ## Geometric proof

These are the lines you need to add.

Sorry it is so messy.