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Chapter 7 Lesson 4. Objective: To find the area of a trapezoid, kite and a rhombus. height of a trapezoid: the perpendicular distance h between the bases. Base. b 1. Leg. Leg. h. b 2. Base.
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Chapter 7 Lesson 4 Objective: To find the area of a trapezoid, kite and a rhombus.
height of a trapezoid:the perpendicular distance h between the bases. Base b1 Leg Leg h b2 Base Theorem7-10:Area of a Trapezoid The area of a trapezoid is half the product of the height and the sum of the bases. b1 h b2
Example 1:Find Area of a Trapezoid Find the area of a trapezoid with height 7 cm and bases 12 cm and 15 cm.
Example 2:Find Area of a Trapezoid Find the area of a trapezoid with height 18 cm and bases 20 cm and 36 cm.
Example 3:Finding Area Using a Right Triangle Find the area of the trapezoid. Leave your answer in simplest radical form. 5cm 5cm Since you do not have the height of the trapezoid we will have to draw it in. h 60° 7cm 2cm 5cm Find h. Find area.
Example 4:Finding Area Using a Right Triangle Find the area of the trapezoid. Leave your answer in simplest radical form. 11cm Since you do not have the height of the trapezoid we will have to draw it in. h 60° 5cm 16cm 11cm Find h. Find area.
Theorem 7-11: Area of a Rhombus or a Kite The area of a rhombus or a kite is half the product of the lengths of its diagonals. d2 d1 Rhombuses and kites have perpendicular diagonals.
Example 5: Finding the Area of a Kite Find the area of kite KLMN. L KM=2+5=7 LN=3+3=6 3m 2m M K 5m 3m N
Example 6: Finding the Area of a Kite Find the area of kite KLMN. L KM=1+4=5 LN=3+3=6 3m 1m M K 4m 3m N
Example 7: Finding the Area of a Kite Find the area of kite with diagonals that are 12 in. and 9 in. long.
The diagonals of a rhombus bisect each other. Example 8: Finding the Area of a Rhombus B 15m Find the area of rhombus ABCD. ∆BEC is a right triangle. Use the Pythagorean Theorem to find BE. E A C 12m AC=12+12=24 BD=9+9=18 D
Example 9: Finding the Area of a Rhombus B 13m Find the area of rhombus ABCD. ∆BEC is a right triangle. Use the Pythagorean Theorem to find BE. 24m E A C 12m 12m AC=12+12=24 BD=5+5=10 D
Assignment Page 376 #2-38 (evens)