Question

Question 8
In $\Delta PQR,\angle P={70}^{\circ }$ and $\angle R={30}^{\circ }$ which side of this triangle is the longest? Give reason for your answer.

Answer 1

Given in $\Delta PQR,\angle P={70}^{\circ }$ and $\angle R={30}^{\circ }$
We know that, sum of all the angles of a triangle is ${180}^{\circ }$
$\therefore \angle P+\angle Q+\angle R=180$

$\angle Q={180}^{\circ }-({70}^{\circ }+{30}^{\circ })={80}^{\circ }$
Here, $\angle Q$ is the biggest angle, so side PR is the longest side.
[Since in a triangle, the side opposite to the largest angle in the longest]