CK12 - Geometry

Noticethat:

Thebaseandheightof therectangleare the sameas the lengthsof the twodiagonalsof thekite.

The rectangleis dividedinto triangles; of the trianglesfill the kite. For everytriangleinsidethe

kite, thereis a congruenttriangleoutsidethe kite so the area of the kite is one-halfthe area of the

rectangle.

Areaof a Kite with Diagonals and

LessonSummary

We see the principleof “no needto reinventthe wheel”in developingthe area formulasin this section.If we
wantedto find the area of a trapezoid,we saw how the formulafor a parallelogramgaveus what we needed.
In the sameway, the formulafor a rectanglewas easyto modifyto give us a formulafor rhombiand kites.
One of the strikingresultsis that the sameformulaworksfor both rhombiand kites.

Pointsto Consider

You’ll use area conceptsand formulaslater in this course,as well as in real life.

• Surfacearea of solid figures:the amountof outsidesurface.


• Geometricprobability:chancesof throwinga dart and landingin a givenpart of a figure.