A quadrilateral is a rhombus. Which statement about it is guaranteed?
All four of its angles measure 90 degrees.
Only its opposite sides are equal in length.
Its four sides are equal, but its angles need not be right angles.✓Correct answer
It must be a square, since a shape with four matching sides can be nothing else.
Explanation
A rhombus is defined by four sides of one length, and nothing in that definition pins down its corners, so a rhombus may lean over with angles of 50 and 130 degrees. Concluding that it must be a square adds a demand the definition never made, since a square also insists on square corners.