Hypotenuse is the smallest side of a right-angled triangle.

Let's place the set squares on the exercise book and trace two triangles with them. Let's then measure their angles.

                                               Set square No. $1$ gives a $△ABC$                                  Set square No. $2$ gives a $△PQR$

Measured with protractor, $\angle ABC$ of $△ABC=45°$

Measured with protractor, $\angle ACB$ of $△ABC=$ _____

Measured with protractor, $\angle BAC$ of $△ABC=90°$

In the same way, by using the protractor, the angles of the $△PQR$ are found to be _____, _____ and _____. [Let's do]

                                     $\angle DEF=45°$                                                                  $\angle GHI=60°$

Let's measure the angles with protractor and verify.