Question

Classify the following triangles.

$∆GHI$ with $m\angle G=20°,m\angle H=70°,andm\angle I=90°$.

Answer 1

Here, $m\angle I=90°$.

i.e., one of the angles is $90°.$

Since, in any triangle, if one of the angles is $90°$, then it is a right angled triangle.

Hence, $∆GHI$ is a right-angled triangle.