Circumference & Area of Circles

Front

What is the formula for the circumference of a circle?

Back

The circumference (C) of a circle is calculated using the formula: C = πd, where d is the diameter of the circle.

Tags

CCSS.7.G.B.4

Front

What is the value of π (pi) commonly approximated as?

Back

π (pi) is commonly approximated as 3.14.

Tags

CCSS.HSG.GMD.A.1

Front

If the diameter of a circle is 10 inches, what is the radius?

Back

The radius (r) is half of the diameter. Therefore, if the diameter is 10 inches, the radius is 5 inches.

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

How do you convert diameter to radius?

Back

To convert diameter to radius, divide the diameter by 2.

Tags

CCSS.7.G.B.4

Front

If a circle has a radius of 7 cm, what is its circumference?

Back

Using the formula C = 2πr, the circumference is C = 2 × 3.14 × 7 = 43.96 cm.

Tags

CCSS.7.G.B.4

Front

What is the area of a circle with a radius of 4 meters?

Back

Using the formula A = πr², the area is A = 3.14 × (4)² = 50.24 square meters.

Tags

CCSS.7.G.B.4

Front

What is the relationship between diameter and circumference?

Back

The circumference of a circle is directly proportional to its diameter, expressed as C = πd.

Tags

CCSS.7.G.B.4

Front

If the circumference of a circle is 31.4 cm, what is the diameter?

Back

Using the formula C = πd, the diameter can be found as d = C/π. Therefore, d = 31.4/3.14 = 10 cm.

Tags

CCSS.7.G.B.4

Front

What is the circumference of a circle with a radius of 10 feet?

Back

Using the formula C = 2πr, the circumference is C = 2 × 3.14 × 10 = 62.8 feet.

Tags

CCSS.7.G.B.4