SB En Geom 10­2 Completed.notebook
November 19, 2012
Lesson 10­2 Areas of Trapezoids, Rhombuses, and Kites
Thm 10­4
Area of a Trapezoid
b1
h
b2
A = ½h(b1 + b2)
Expl 1. The area of Arkansas 250 mi
242 mi
190 mi
Ckpt 1. Find the area of a trapezoid with height 7 cm and bases 12 cm and 15 cm.
Nov 17­4:58 PM
Expl 2. Find area using a right triangle in radical form.
S 5m
R
P
60
7m
Q
Ckpt 2. In Example 2, suppose h is made smaller so that m<P=45 while bases angles R and Q are unchanged. Find the area of trapezoid PQRS.
Nov 17­5:03 PM
1
SB En Geom 10­2 Completed.notebook
Thm 10­5
November 19, 2012
Area of a Rhombus or Kite
d2
A = ½d1d2
d1
d1
d2
Expl 3. Find the area of the kite.
L
K 2m
3m
5m
3m
M
N
Nov 17­5:07 PM
Ckpt 3. Find the area of a kite with diagonals that are 12 in. and 9 in. long.
Ckpt 4. Find the area of a rhombus.
B
15 m
12 m
A
C
E
D
Nov 17­5:12 PM
2
SB En Geom 10­2 Completed.notebook
November 19, 2012
Ckpt 4. In Example 4, explain how you can use a Pythagorean Triple to conclude that BE = 9. Extra.
A
Find the area of the trapezoid. 11 ft
B
13 ft
D
16 ft
C
Nov 17­5:15 PM
Homework
Lesson 10-2
1-16, 20-28,
30-32, 38-40
Nov 17­5:18 PM
3