Area of a circle

Front

What is the formula for the area of a circle?

Back

The area A of a circle is given by the formula A = πr², where r is the radius of the circle.

Tags

CCSS.7.G.B.4

Front

How do you express the area of a circle in terms of π?

Back

To express the area of a circle in terms of π, use the formula A = πr² and leave the answer in that form without calculating the numerical value.

Tags

CCSS.7.G.B.4

Front

If the radius of a circle is 2 cm, what is the area in terms of π?

Back

The area is 4π cm².

Tags

CCSS.7.G.B.4

Front

What is the approximate value of π?

Back

The approximate value of π is 3.14.

Tags

CCSS.HSG.GMD.A.1

Front

How do you calculate the area of a circle to one decimal place?

Back

Calculate the area using A = πr², then round the result to one decimal place.

Tags

CCSS.7.G.B.4

Front

What is the area of a circle with a radius of 7 ft?

Back

The area is 49π ft² or approximately 153.9 ft².

Tags

CCSS.7.G.B.4

Front

If a circle has an area of 25π cm², what is its radius?

Back

The radius is 5 cm, since A = πr² implies r = √(A/π) = √(25) = 5.

Tags

CCSS.7.G.B.4

Front

What is the relationship between diameter and radius in a circle?

Back

The diameter d of a circle is twice the radius r, so d = 2r.

Front

How do you convert the area of a circle from terms of π to a decimal?

Back

Multiply the area in terms of π by the approximate value of π (3.14) to convert it to a decimal.

Tags

CCSS.7.G.B.4

Front

What is the area of a circle with a radius of 10 cm?

Back

The area is 100π cm² or approximately 314.0 cm².

Tags

CCSS.7.G.B.4