The circumference of the circle is 50? feet .

1
example 1
The circumference of the circle is 50? feet
. The area of the shaded region ________
2
The circumference of the circle is 50? feet
. The area of the shaded region ________
50
C ? d 50? therefore the diameter of the
circle is 50 feet.
3
The circumference of the circle is 50? feet
. The area of the shaded region ________
25
C ? d 50? therefore the diameter of the
circle is 50 feet and the radius is 25 feet .
4
The circumference of the circle is 50? feet
. The area of the shaded region ________
25
C ? d 50? therefore the diameter of the
circle is 50 feet and the radius is 25 feet .
The area of the circle ? (25)2 625 ?
square feet
the area of the square 50x50 2500 square
feet
5
The circumference of the circle is 50? feet
. The area of the shaded region ________
25
C ? d 50? therefore the diameter of the
circle is 50 feet and the radius is 25 feet .
The area of the circle ? (25)2 625 ?
square feet
2500 square feet
- 625 ? square feet
6
The circumference of the circle is 50? feet
. The area of the shaded region (2500 - 625 ? )
square feet
25
C ? d 50? therefore the diameter of the
circle is 50 feet and the radius is 25 feet .
The area of the circle ? (25)2 625 ?
square feet
2500 square feet
- 625 ? square feet
7
example 2
The circumference of the circle is 50? feet
. The area of the shaded region ________
8
The circumference of the circle is 50? feet
. The area of the shaded region ________
C ? d 50? therefore the diameter of the
circle is 50 feet.
9
The circumference of the circle is 50? feet
. The area of the shaded region ________
50
x
C ? d 50? therefore the diameter of the
circle is 50 feet.
x
Let x the side of the square
10
The circumference of the circle is 50? feet
. The area of the shaded region ________
50
x
C ? d 50? therefore the diameter of the
circle is 50 feet.
x
Let x the side of the square
x2 x2 502 2500
x2 1250 the area of the square
area of circle 625 ?
11
The circumference of the circle is 50? feet
. The area of the shaded region ________
50
x
C ? d 50? therefore the diameter of the
circle is 50 feet.
x
Let x the side of the square
x2 x2 502 2500
x2 1250 the area of the square
area of circle 625 ?
- area of square 1250
12
The circumference of the circle is 50? feet
. The area of the shaded region (625 ? - 1250)
sq feet
50
x
C ? d 50? therefore the diameter of the
circle is 50 feet.
x
Let x the side of the square
x2 x2 502 2500
x2 1250 the area of the square
area of circle 625 ?
- area of square 1250
13
example 3
AB 30 feet
A
30
B
What is the SUM of the areas of the purple
squares?_________
14
example 3
AB 30 feet
A
30
x
x
B
y
y
What is the SUM of the areas of the purple
squares?_________
Let x the length of the side of the large
square and let y the
length of the side of the small square
15
example 3
AB 30 feet
A
Area x2
30
x
x
B
y
Area y2
y
What is the SUM of the areas of the purple
squares? x2 y2
Let x the length of the side of the large
square and let y the
length of the side of the small square
16
example 3
AB 30 feet
A
Area x2
30
x
x
B
y
Area y2
y
What is the SUM of the areas of the purple
squares? x2 y2 302 900 sq ft
Let x the length of the side of the large
square and let y the
length of the side of the small square
17
example 4
10 feet
If the area of the triangle is 14 square feet,
then the area of the rectangle is ____________
7 feet
18
example 4
10 feet
If the area of the triangle is 14 square feet,
then the area of the rectangle is ____________
The area of a triangle ½ height x base
7 feet
14 ½ height x 7
28 height x
7
4 height
19
example 4
10 feet
If the area of the triangle is 14 square feet,
then the area of the rectangle is 10 x 4 40 sq
ft
4
The area of a triangle ½ height x base
7 feet
14 ½ height x 7
28 height x
7
4 height