Question

$ABCD$ is a paralleogram. If its diagonals are equal, then find the value of $\angle ABC$

Answer 1

In a parallelogram, if two diagonals are equal the parallelogram is a rectangle.

So, $ABCD$ is a rectangle. It is known that each interior angle of the rectangle is ${90}^o$.

Since, $ABC$ is an interior angle rectangle $ABCD$, it will be ${90}^o$.

Hence, $\angle ABC={90}^o$.