How to calculate roots when the equation is non quadratic?

Select the lengths in centimeters that would form a right triangle

Apool measures 100 meters by 100 meters a toddler inside the pool and trows a ball 60 centimeters from one edge of the pool.how far is the ball from the opposite edge of the pool

When i'm with my factor 5, my prodect is 20 .when i'm with my addend 6' my sum is 10.what number am i