Circumference and Area of Circles Part1

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

How do you calculate 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 the relationship between diameter and radius?

Back

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

Front

If a circle has a radius of 10 ft, what is its circumference?

Back

Using the formula C = 2πr, the circumference is C = 2π(10) ≈ 62.83 ft.

Front

What is the area of a circle with a radius of 5 cm?

Back

Using the formula A = πr², the area is A = π(5)² ≈ 78.54 cm².

Front

How do you find the perimeter of a semicircle?

Back

The perimeter (P) of a semicircle is calculated as P = πr + 2r, where r is the radius.

Front

What is the circumference of a circle with a diameter of 14 cm?

Back

Using the formula C = πd, the circumference is C = π(14) ≈ 43.98 cm.

Front

How many square feet are in a circle with a radius of 7.5 ft?

Back

Using the formula A = πr², the area is A = π(7.5)² ≈ 176.63 ft².

Front

What is the area of a circular lawn with a radius of 20 ft?

Back

Using the formula A = πr², the area is A = π(20)² ≈ 1256.64 ft².

Front

If a circular garden has a radius of 6 ft, how much fencing is needed?

Back

The amount of fencing needed is equal to the circumference, which is C = 2π(6) ≈ 37.68 ft.