If the diagonal of a rhombus is equal to its side, then the angles of the rhombus are:
Answer: D
Let the rhombus be ABCD with side length 's'. If the diagonal AC is also 's', then \(\triangle ABC\) has all three sides equal to 's'. This means \(\triangle ABC\) is an equilateral triangle, and all its angles are 60°.
So, \(\angle B = 60°\). The opposite angle, \(\angle D\), is also 60°.
Adjacent angles in a rhombus are supplementary. So, \(\angle A = 180° - 60° = 120°\). The opposite angle, \(\angle C\), is also 120°.
The angles are 60°, 120°, 60°, 120°.