Area of Circle

What is the area of the shaded picture?

• 616 cm²

• 314 cm²

• 302 cm²

• 50.24 cm²

Answer explanation

π for bigger circle = 22/7

π for smaller circle = 3.14

radius bigger circle = 14 cm

radius smaller circle = 10 cm

area of shaded picture = big - small

bigger circle = 22/7 x 14 x 14 = 616 cm²

smaller circle = 3.14 x 10 x 10 = 314 cm²

shaded picture = 616 - 314 = 302 cm²

or

area of shaded picture = big - small

= π x R x R - π x r x r

= π (R² - r²)

= 3.14 (14² - 10²)

= 3.14 x (196 - 100) = 3.14 x 96 = 301.44 cm²

What is the area of the circle?

• 62.8 cm²

• 125.6 cm²

• 314 cm²

• 1256 cm²

Answer explanation

Data :

Diameter = 20 cm

radius = 10 cm

Area = π x r x r

= 3.14 x 10 x 10

= 314 cm²

Tags

CCSS.7.G.B.4

Look at the picture. Father wants to plant the grass on the circular garden. What is the area of the grass does father need?

• 22 m²

• 44 m²

• 154 m²

• 616 m²

Answer explanation

Data :

radius = 7 m

Area = π x r x r

= 22/7 x 7 x 7

= 154 m²

Tags

CCSS.7.G.B.4

What is the area of the circle if the diameter of the circle is 40 cm?

• 62.8 cm²

• 125.6 cm²

• 1256 cm²

• 5024 cm²

Answer explanation

Data :

diameter = 40 cm

radius = 20 cm

Area = π x r x r

= 3.14 x 20 x 20

= 1256 cm²

Tags

CCSS.7.G.B.4

What is the area of the circle if the diameter of the circle is 28 cm?

• 44 cm²

• 88 cm²

• 616 cm²

• 2464 cm²

Answer explanation

Data :

diameter = 28 cm

radius = 14 cm

Area = π x r x r

= 3.14 x 14 x 14

= 616 cm²

Tags

CCSS.7.G.B.4

What is the area of the circle if the radius of the circle is 3 m?

• 3.14 m²

• 9.42 m²

• 18.84 m²

• 28.26 m²

Answer explanation

Data :

radius = 3 m

Area = π x r x r

= 3.14 x 3 x 3

= 28.26 m²

Tags

CCSS.7.G.B.4