11.4 areas of kites and related figures
DESCRIPTION
11.4 Areas of Kites and Related Figures. Two formulas. A kite = A △ ABD + A △ DBC. A. DB = 10m AE = 5 m EC = 12 m BC = 13mTRANSCRIPT
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11.4 Areas of Kites and Related Figures
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A kite = A △ABD + A △ DBC
B
C
D
Two formulas
ADB = 10m
AE = 5 m
EC = 12 m
BC = 13m
<BAD is a right angle
Find the area of the kite.
E
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Use correct formula
A kite = A ABD + A DBC△ △
= ½ (BD)(AE) + ½(BD)(EC)
= ½(10)(5) + ½ (10)(12)
= 25 + 60
= 85 m2
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T105: The area of a kite equals half the product of its diagonals.
A kite = d1d22
1
A kite = ½ (10)(17)
= 85m2
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Find the area of a kite with diagonals 9 and 14
Draw, label, write all steps.
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Find the area of a rhombus whose perimeter is 20 and whose longer diagonal is 8.
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What do you know about the inside triangles?
5
5
4
3
Remember: a rhombus is a parallelogram so the diagonals bisect each other. It is also a kite, so its diagonals are perpendicular to each other.
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