Wednesday, September 5, 2007

a geometry question - 4


AB = BC = CA
BD = 8
CD = 7
AD = 5
Find the BDA angle.

Answer:
120°
(The solution method other than a "brute force" method eludes me. I prepared this question 12 years ago, and I assume there was an easier method. If anybody knows such a method, let me know at karakusk at yahoo dot com.)

Tuesday, September 4, 2007

a geometry question - 3


BD =DC and AE = EC given.

Find the unknown angle.

Answer:
20°

Monday, September 3, 2007

a geometry question - 2


Find the unknown angle.

Answer:
70°

a geometry question - 1


Find the unknown angle.

Answer:
130°