Question

ABCD is a parallelogram. If two diagonals are equal find angle ABC

Answer 1

if diagonal are equall then it will be a rectangle
so.... all angle of the rectangle is 90
hence all angle is 90

Answer 2

since it is given that the diagonal are equal and it is a parallelogram it forms a rectangle. A rectangle is a special type of parallelogram with all angles as 90° and diagonal equal.

Hence the measure of ∠ABC = 90°