since its a right triangle, you can use a² + b² = c²
one of the legs is a and the other leg is b it doesn't matter which one because its addition and works the same way c needs to be the hypotenuse
so its a² + 48² = 50²
a² + 2304 = 2500
- 2304 -2304
a² = 196
√a² = √196
a = 14
