Answer:
A
Step-by-step explanation:
Using Pythagoras' identity on the large right triangle.
The square on the hypotenuse is equal to the sum of the squares on the other 2 sides, that is
(x + 32)² = 30² + 40² = 900 + 1600 = 2500 ( take the square root of both sides)
x + 32 =[tex]\sqrt{2500}[/tex] = 50 ( subtract 32 from both sides )
x = 18 → A
