Answer:
x= 60
Step-by-step explanation:
if y is the other missing side
y^2 = 64^2 + 48^2
y^2 = 4,096 + 2,304
y^2 = 6,400
100^2 = x^2 +y^2
x^2 = 10,000 - 6,400
x^2 = 3,600
x = 60
