Rhombus Activity

A rhombus is a parallelogram with all sides congruent.

Hand each student a 8 ˝ x 11 sheet of paper.

Show the students how to fold their sheet of paper into a rhombus.

    “Fold the sheet of paper making a pair of opposite sides fall upon each other and crease.  Repeat with the other pair of opposite sides.  Where the creases intersect the side is the midpoint of the side.  Picking a vertex of the paper, fold the vertex interior to the sheet of paper creating a crease extending from the midpoin of one side of the vertex to the midpoint of the other side of the vertex.  Repeat with the other vertices of the paper.  The resulting figure is a rhombus.”
These directions are from one of the session at the GCTM Conference at Rock Eagle -- 2001.  

Fold the rhombus in half along one of its diagonals.  What do you notice about the angles that are created by the diagonal?
They are congruent.

Fold the rhombus in half along the other diagonal.  What do you notice about the angles that are created by the diagonal?
They are congruent.
Each diagonal of a rhombus bisects a pair of opposite angles.

How many lines of symmetry does a rhombus have?  2

What do you notice about the pairs of segments that the diagonals divide each other into? 
Each diagonal divides the other diagonal in half.  They bisect each other.

Look at the angles that are formed by the two diagonals.  What do you notice? 
They are right angles.  The diagonals are perpendicular.

What can you conclude about the diagonals of a rhombus?
Each diagonal of a rhombus is the perpendicular bisector of the other.

What other properties does a rhombus have?
Since a rhombus is also a parallelogram, opposite sides are congruent, opposite angles are congruent, and consecutive angles are supplementary.