Midpoints of the Sides of a Rhombus

Proposed Problem 2

What is the figure formed by joining the midpoints of the adjacent sides of a rhombus?







Conjecture

The figure formed by joinig the midpoints of the sides of a rhombus is a rectangle.






Hint

A rectangle is a quadrilateral with four right angles.

Please enable Java for an interactive construction (with Cinderella).
Drag free elements (free points A and B, semi free point C, or the side BC) to alter the rhombus ABCD and observe the measurment of the angles of the figure EFGH, which is formed by joining the midpoints of the adjacent sides of the rhombus ABCD to check the correctness of the made conjecture.