Question

Can the sides 21, 28, 35 be a right triangle?

Answer 1

Yes, it can be a right triangle.

Explanation:

Letss try using Pythagoras Theorem with `c=35` as hypotenuse, you get:
`c^2=a^2+b^2`
`35^2=21^2+28^2`
`1225=441+784=1225` YES!