Step: 1

Circumference of the circle, c = 45 ft.

[Given.]

Step: 2

Circumference of a circle = 2 × π × r .

[Formula.]

Step: 3

= 2 × 3.14 × r = 45

[Substitute.]

Step: 4

[Divide each side by (2 × 3.14).]

Step: 5

= 7.16 ft

[Simplify.]

Step: 6

Area of the circle = π r ^{2} = 3.14 × 7.16 × 7.16

[Substitute r = 7.16.]

Step: 7

= 160.97 sq.ft

[Simplify.]

Step: 8

The area of the circle is 160.97 sq. ft.

Correct Answer is : 160.97 sq. ft.

Step: 1

The radius of the pizza = Diameter 2 = 8 2

[Substitute d = 8.]

Step: 2

= 4 inches

Step: 3

Area of a circle = π r ^{2}.

[Formula.]

Step: 4

= π × 4^{2}

[Substitute the values.]

Step: 5

= 3.14 × 16

[Substitute π = 3.14.]

Step: 6

= 50.2 in.^{2}

Correct Answer is : 50.2 in.^{2}

Step: 1

The area of a circle = π r ^{2}

Step: 2

π × (1.6)^{2}

Step: 3

= 3.14 × 2.56

[Substitute π = 3.14.]

Step: 4

= 8.03 miles^{2}.

Correct Answer is : 8.03 miles^{2}

Step: 1

Circumference of a circle = 2π r

Step: 2

2 x 3.14 x r = 83

[Substitute π = 3.14.]

Step: 3

[Divide each side by (2 x 3.14).]

Step: 4

= 13.21 ft.

Step: 5

Area of the bottom = π r ^{2}

Step: 6

= 3.14 x 13.21 x 13.21

[Substitute r = 13.21.]

Step: 7

= 547.94 ft.^{2}

Step: 8

The area of the bottom is about 547.94 ft^{2}.

Correct Answer is : 547.94 ft^{2}

Step: 1

Area of the circular region where the goat can graze = π r ^{2}

Step: 2

= 3.14 × 3 × 3

[Substitute r = 3 and π = 3.14.]

Step: 3

= 28.26 m.^{2}

Step: 4

The area the goat has to graze is 28.26 m^{2}.

Correct Answer is : 28.26 m^{2}

Step: 1

Circumference of the circle = 2πr = 40 cm.

Step: 2

2πr = 40

Step: 3

πr = 40 2

[Divide each side by 2.]

Step: 4

[Divide each side by π .]

Step: 5

Area of the circle = πr ^{2}

Step: 6

= π × (20 π )^{2}

[Substitute r = 50 π .]

Step: 7

= 400 π cm^{2}.

Correct Answer is : 400 π cm^{2}

Step: 1

Radius of the outer circle = 39 m

Step: 2

Area of the outer circle = π r ^{2}

Step: 3

= π x 39^{2}

[Substitute r = 39.]

Step: 4

= 1521π m^{2}

[Multiply.]

Step: 5

Radius of the inner circle = 39 - 2 = 37 m

Step: 6

Area of the inner circle = π r ^{2}

Step: 7

= π x 37^{2}

[Substitute r = 37.]

Step: 8

= 1369π m^{2}

[Multiply.]

Step: 9

Area of the path = Area of the outer circle - Area of the inner circle

Step: 10

= 1521π - 1369π

[Substitute the values.]

Step: 11

= 152π

[Subtract.]

Step: 12

Area of the path is 152π m^{2}.

Correct Answer is : 152π m^{2}

Step: 1

The radius of the pizza = Diameter 2 = 10 2

[Substitute d = 10.]

Step: 2

= 5 inches

Step: 3

Area of a circle = π r ^{2}.

Step: 4

= π × 5^{2}

[Substitute the values.]

Step: 5

= 3.14 × 25

[Substitute π = 3.14.]

Step: 6

= 78.5 in.^{2}

Correct Answer is : 78.5 in.^{2}

Step: 1

The area of a circle = π r ^{2}

Step: 2

= π × (1.6)^{2}

Step: 3

= 3.14 × 2.56

[Substitute π = 3.14.]

Step: 4

= 8.04 yd^{2}

Correct Answer is : 8.04 yd^{2}

Step: 1

Circumference of a circle = 2π r

Step: 2

2 × 3.14 × r = 73

[Substitute π = 3.14.]

Step: 3

[Divide each side by (2 × 3.14).]

Step: 4

= 11.62 ft

Step: 5

Area of the bottom = π r ^{2}

Step: 6

= 3.14 × 11.62 × 11.62

[Substitute r = 11.62.]

Step: 7

[Simplify.]

Step: 8

The area of the bottom is about 423.98 ft^{2}.

Correct Answer is : About 423.98 ft^{2}

Step: 1

Area of the circular region where the goat can graze = π r ^{2}

Step: 2

= 3.14 × 3 × 3

[Substitute r = 3 and π = 3.14.]

Step: 3

= 28.26 m^{2}

Step: 4

The area of the circle the goat can graze is 28.26 m^{2}.

Correct Answer is : 28.26 m^{2}

Step: 1

Diameter of the disk = 8 in.

Step: 2

Radius of the disk = diameter 2 = 8 2 = 4 in.

Step: 3

Area of the disk = π r ^{2}

[Formula.]

Step: 4

= 3.14 × 4^{2}

[Substitute the value of π and r .]

Step: 5

= 3.14 × 16

Step: 6

= 50.24

[Simplify.]

Step: 7

So, area of the disk of diameter 8 in. is 50.24 in.^{2}

Correct Answer is : 50.24 in.^{2}

Step: 1

Diameter of the nickel = 22 mm

Step: 2

Radius of the nickel = diameter 2 = 22 2 = 11 mm

Step: 3

Area of the nickel = π r ^{2}

[Formula.]

Step: 4

= 3 × ( 11 )^{2}

[Substitute the values of π and r .]

Step: 5

= 3 × 121

[Simplify.]

Step: 6

= 363

Step: 7

= 363 mm^{2}

[Round to the nearest millimeter.]

Correct Answer is : 363 mm^{2}

- Complementary, Supplementary, Vertical and adjacent Angles-Gr 7-Solved Examples
- Finding Missing Angles in Polygons-Gr 7-Solved Examples
- Scale Drawings-Gr 7-Solved Examples
- Application Problems involving Scale Drawings-Gr 7-Solved Examples
- Circumference of Circles-Gr 7-Solved Examples
- Perimeter and Area of Composite Figures-Gr 7-Solved Examples

- Circle