Hi there!
For the Pythagorean Theorem, basically you just need to apply this formula: a^2 + b^2 = c^2
And then find the root of the hypotenuse.
For example,
15^2 + 8^2 = the hypotenuse^2
Which equals, 225 + 64 = 289
Square root of 289 = 17
Please mark me brainliest if this helps!
Have a wonderful day!