Charmaine is building a kite from string and a wooden frame. She wants to be sure that the string around the frame forms a parallelogram. Let's take a look at the picture of a top of the kite.
The top of the kite is in the shape of a quadrilateral. The sides of this quadrilateral are made of string and the diagonals are made of the wooden frame. We want to use the measures of the wooden frame to prove that the string forms a parallelogram. Therefore, we should consider the Condition of Parallelograms that refers to diagonals.
Theorem 6.11
If the diagonals of of a quadrilateral bisect each other, then this quadrilateral is a parallelogram.
If Charmaine can find the measures of the wooden portion of a frame, she can use this condition to prove that the string forms a parallelogram. If AP=PC and DP=PB, then the string will form a parallelogram.
