MEASURING CIRCLES TEST REVIEW

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.

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.

Front

What is π (pi)?

Back

π (pi) is a mathematical constant approximately equal to 3.14, representing the ratio of a circle's circumference to its diameter.

Front

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

Back

The radius (r) is half of the diameter. Therefore, r = 10 cm / 2 = 5 cm.

Front

What is the circumference of a circle with a radius of 4 cm?

Back

Using the formula C = 2πr, the circumference is C = 2π(4) = 8π cm, approximately 25.12 cm.

Front

If the radius of a circle is 5 inches, what is its area in terms of π?

Back

Using the formula A = πr², the area is A = π(5)² = 25π square inches.

Front

What is the value of 3π?

Back

3π is approximately equal to 9.42.

Front

If the radius of a circle is doubled, how does the area change?

Back

If the radius is doubled, the area increases by a factor of four, since area is proportional to the square of the radius.

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, where d is the diameter.

Front

What is the area of a circle with a radius of 3 inches in terms of π?

Back

The area is A = π(3)² = 9π square inches.