This subject is pythagorean theorem

Answer:
x = 170
Step-by-step explanation:
Formula: a² + b² = c²
a = side of right triangle (known as the leg)
b = side of right triangle (also known as the leg)
c = hypotenuse
So we will find the C (x).
a² + b² = c²
136² + 102² = c² (evaluate both 136 and 102.)
18,496 + 10,404 = c² (Add)
28,900 = c²
Now all we need to do is find the square root of 28,900.
√28,900 = √C²
170 · 170 = 28,900
So:
170 = C
x = 170