What is the length of the hypotenuse, x, if (20, 21, x) is a Pythagorean triple?

Question

alexalas · Answer

well a^2 + b^2=c^2
a=20
b=21
a Pythagorean triple all sides are whole numbers like 1,2,3,4,5,6,7,8,9,10....

anonymous · Answer

the choices are 22 29 41 42

alexalas · Answer

a^2 + b^2= ? find ?

anonymous · Answer

Answer and get a medal

alexalas · Answer

I am sorry I will not give direct answers. You give me the answer I tell you if you got it correct. Do not start guessing or I will leave. I want you to work it out so I know you know how to do it. okay?

alexalas · Answer

well a^2 + b^2=c^2
a=20
b=21
find c^2

anonymous · Answer

after you find a^2 And B^2 do you divide?

anonymous · Answer

i am confused.

anonymous · Answer

it would be 29?

alexalas · Answer

let me give you a few examples 
|dw:1429819301557:dw|
3^2+4^2=25
the you square root
square root is what times itself = this number
so 5*5=25
so the square root of 25 is 5