Answer:
x=5
Explanation:
Plugin the number into sthe pythagroyean theorm (a²+b²=c²), with 3 replacing a, 4 replacing b, and x replacing c.
3²+4² = x²
9+16 = x²
25 = x²
√25 = √x²
x = 5
It's helpful to remember that if the opposite and adjacent sides of the triangle (in this case CB and AB) are the lengths 3 and 4, the hypotenuse (longest side of the triangle) is always equal to 5.