Choice 1. He did not square 40, he just multiplied by 2.
Step-by-step explanation:
Step 1:
According to the Pythagorean theorem, the square of the hypotenuse is equal to the sum of the squares of the other two sides.
The hypotenuse measures c cm while the other sides are 40 cm and 9 cm each.
Step 2:
According to the Pythagorean theorem,
This is the correct solution to the given problem. Hans did not square 40, he just multiplied by 2. Which is the first option.