What’s 1 and what’s 2 ?

Answer:
For question 1:
The length of hypotenuse expression =√(8^2+9^2)
For question 2:
The expression for length a is
a=√(15^2-4^2)
Step-by-step explanation:
For question 1:
The length of hypotenuse expression =√(8^2+9^2)
For question 2:
Then expression for length a is
a=√(15^2-4^2)