Answer:
Note that the sum of the angles in a triangle are 180.
1. B. <R = 180 - 70 -55 = 55. Since <R = <T, then RS = ST
2. D. <J = 180 - 42 -96 = 42 = <K, so JL = KL = 12
3. B. Let the base angle = x. The vertex angle = 2x + 50. The sum of the angles in a triangle is 180, so x + x + 2x + 50 = 4x + 50 = 180 -> 4x = 130 -> x = 32.5.
4. D. Since <S = <Q, RQ = RS. Thus, 2x + 4 = 18 -> 2x = 14 -> x =7
I hope this helps!
