Both triangle are isosceles, which means their base angles are congruent.
54 + 2y = 180
2y = 126
y = 63
The measure of the base angles of the triangle on the left is 63 degrees.
180 - 63 = 117
117 + 2x = 180
2x = 63
x = 31.5
Answer:
x = 31.5
Hope this helps.