Solve for X (hypotenuse)
Hypotenuse = [tex] \sqrt{a^{2}+b^{2}} [/tex]
Substitute 20 for A and 21 for B
[tex] \sqrt{20^{2}+21^{2}} [/tex]
Solve exponents
20^2 = 400
21^2 = 441
Hypotenuse = [tex] \sqrt{400 + 441} [/tex]
Add
400 + 441 = 841
Hypotenuse = [tex] \sqrt{841} [/tex]
Solve square root
[tex] \sqrt{841}[/tex] = 29
Hypotenuse = 29