CK-12 Geometry Concepts

http://www.ck12.org Chapter 6. Polygons and Quadrilaterals

Watch this video for help with the Examples above.

MEDIA

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CK-12 Foundation: Chapter6KitesB

Concept Problem Revisited

If the diagonals (pieces of wood) are 36 inches and 54 inches,xis half of 36, or 18 inches. Then, 2xis 36. To
determine how large a piece of canvas to get, find the length of each side of the kite using the Pythagorean Theorem.

182 + 182 =s^2182 + 362 =t^2

324 =s^21620 =t^2

18

√

2 ≈ 25. 5 ≈s 18

√

5 ≈ 40. 25 ≈t

The perimeter of the kite would be 25. 5 + 25. 5 + 40. 25 + 40. 25 = 131 .5 inches or 11 ft, 10.5 in.

Vocabulary

Akiteis a quadrilateral with two distinct sets of adjacent congruent sides. The angles between the congruent sides
are calledvertex angles.The other angles are callednon-vertex angles.

If a kite is concave, it is called adart.

Guided Practice

KIT Eis a kite.

Find:

1.m^6 KIS

2.m^6 IST

3.m^6 SIT

Answers:

1. m^6 KIS= 25 ◦by the Triangle Sum Theorem (remember that^6 KSIis a right angle because the diagonals are
   perpendicular.)

2.m^6 IST= 90 ◦because the diagonals are perpendicular.

3.m^6 SIT= 25 ◦because it is congruent to^6 KIS.

Practice

For questions 1-6, find the value of the missing variable(s). All figures are kites.