Question

A triangle has side lengths of 20 meters, 10 meters, and 17 meters. What type of triangle is it?

Answer 1

right angle : it can’t be equilateral because all sides would have to be the same length, and it can’t be isosceles because two sides would have to be the same length

Answer 2

Use Pythagoras’ Theorem to figure out if it is scalene or right-angled.

20^2 = 400
10^2 = 100
17^2 = 289

400 + 100 doesn’t equal 289
100 + 289 doesn’t equal 400
400+ 289 doesn’t equal 100

So the triangle can’t have a right angle, so therefore is a SCALENE triangle.