Circumference and Area of a Circle

Front

What is the formula for the circumference of a circle?

Back

The circumference (C) of a circle is calculated using the formula C = 2πr, where r is the radius of the circle.

Tags

CCSS.7.G.B.4

Front

What is the formula for the area of a circle?

Back

The area (A) of a circle is calculated using the formula A = πr², where r is the radius of the circle.

Tags

CCSS.7.G.B.4

Front

If the radius of a circle is 5 m, what is its circumference?

Back

Using the formula C = 2πr, the circumference is C = 2π(5) ≈ 31.42 m.

Tags

CCSS.7.G.B.4

Front

If the radius of a circle is 10 in, what is its area?

Back

Using the formula A = πr², the area is A = π(10)² ≈ 314.16 in².

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.

Tags

CCSS.7.G.B.4

Front

How do you convert the circumference from meters to yards?

Back

To convert meters to yards, multiply the length in meters by 1.09361.

Tags

CCSS.2.MD.A.2

Front

What is the circumference of a circle with a diameter of 8 m?

Back

Using the formula C = πd, the circumference is C = π(8) ≈ 25.13 m.

Tags

CCSS.7.G.B.4

Front

If a circle has an area of 50.24 m², what is its radius?

Back

To find the radius, use the area formula A = πr². Rearranging gives r = √(A/π). For A = 50.24 m², r ≈ 4 m.

Tags

CCSS.7.G.B.4

Front

What is the value of π (pi) approximately?

Back

The value of π (pi) is approximately 3.14.

Tags

CCSS.HSG.GMD.A.1

Front

How do you find the area of a circle if you know the circumference?

Back

First, find the radius using the circumference formula C = 2πr, then use A = πr² to find the area.

Tags

CCSS.7.G.B.4