Please help me!!!!! I really need help on these problems.

6-113. Given AHAT where ZH = 250 and HA = 10. a. What is a possible length of AT that would make two triangles? Sketch a diagram of the triangle to demonstrate. b. What are the possible lengths for AT that will make exactly one triangle? c. For what values of AT will not form a triangle? 6-114. Find the exact value of sec(a + b) where cos a = , tan b = -2, sin a > 0 and csc b