What is the value of the expression? 4 to the second power plus 3 to the 3rd power

Which math sentence can be used to determine if the triangle is a right triangle?

Dakota earned $7.50 in interest in account a and $18.75 in interest in account b after 15 months. if the simple interest rate is 4% for account a and 5% for account b, which account has the greater principal? explain. to make it a little easier, there is an image. good luck!

This is about circle theorems. someone asap : (