Answer:
12350%
Step-by-step explanation:
. 76 - 34 = 42
. 42 divided by 34 = 1.23529411765
. 1.23529411765 multiplied by 100 = 123.529411765
. 123.529411765 ≈ 123.5 * 100 = 12350%
If shapes are congruent, then they are mathematically equal (same dimensions, angles etc.). So just locate where the angle x is on both triangles, it should have a value on or a calculable value on the other. If you provide us with the actual sheet I could walk you through it.