Pythagoras Converse
About this exercise
Deciding whether a triangle has a right angle.
Example problems
A few of the problems this exercise asks. The printable worksheet holds ten fresh ones.
- Are the numbers 7, 24, 26 the sides of a right triangle?
- Are the numbers 12, 35, 40 the sides of a right triangle?
- Are the numbers 7, 24, 27 the sides of a right triangle?
- Are the numbers 5, 12, 16 the sides of a right triangle?
Try it yourself first — open a section below only if you get stuck.
How to solve it
Square the longest side and compare it with the sum of the squares of the other two. Equal means a right angle.
Worked example
5, 12 and 13 works, because 25 + 144 = 169.
Common mistake
Squaring the wrong side. The longest side always stands alone on one side of the comparison.