CK12 - Geometry

rhombi.In this lesson,you’lllearnaboutrulesspecificto theseshapesthat are not true for all parallelograms.

Diagonalsin a Rectangle

Recallfrompreviouslessonsthat the diagonalsin a parallelogrambisecteachother. You can provethis
with congruenceof triangleswithinthe parallelogram.In a rectangle,thereis an evenmorespecialrelationship
betweenthe diagonals.The two diagonalsin a rectanglewill alwaysbe congruent.We can showthis using
the distanceformulaon a coordinategrid.

Example 1

Use the distanceformulato demonstratethat the two diagonalsin the rectanglebeloware congruent.

To solvethis problem,you needto find the lengthsof both diagonalsin the rectangle.First,drawline seg-

mentsthat connectthe verticesof the rectangle.So, drawa segmentfrom to and from

to.

You can use the distanceformulato find the lengthof the diagonals.Diagonal goesfrom

to.

Next,find the lengthof diagonal. That diagonalgoesfrom to.