Yes or No: Is this triangle a Right Triangle with side measures 21, 28, 35?

yes

Step-by-step explanation:

Hello There!

In order for a right triangle to be a right triangle the hypotenuse ( longest side) squared must equal the sum of the two shorter sides squared

so if this is a right triangle then

so as you can see 21^2+28^2 does = 35^2 so the side measures given do make a right triangle