A triangular trellis has angles R, S, and T that measure 73°, 73°, and 34°, respectively. If the length of ST = 4y + 6 and the length of TR = 7y - 21, what is the value of y?

A.5
B.11
C.15
D.9

Question

A triangular trellis has angles R, S, and T that measure 73°, 73°, and 34°, respectively. If the length of ST = 4y + 6 and the length of TR = 7y - 21, what is the value of y?

A.5
B.11
C.15
D.9

anonymous · Answer

Alright, notice what we have now :

R and S have equal angles , so <R = <S

This means we have an isosceles triangle, so both sides are equal :

ST = TR
7y -21 = 4y + 6

Solve for y :
3y = 27
y = 9

^_^ is it clear now?