Flashcardizz 3.1

Front

What is the formula for the circumference of a circle?

Back

The circumference (C) of a circle is given by the formula: C = 2\pi r, where r is the radius.

Front

What is the formula for the area of a circle?

Back

The area (A) of a circle is given by the formula: A = \pi r^2, where r is the radius.

Front

How do you calculate the circumference of a circle using its diameter?

Back

The circumference (C) can also be calculated using the diameter (d) with the formula: C = \pi d.

Front

What is the area of a semi-circle with radius r?

Back

The area (A) of a semi-circle is given by the formula: A = \frac{1}{2}\pi r^2.

Front

Calculate the circumference of a circle with a radius of 8 m. Leave your answer in terms of \pi.

Back

C = 2\pi(8) = 16\pi m.

Front

Calculate the area of a circle with a radius of 7 cm. Leave your answer in terms of \pi.

Back

A = \pi(7^2) = 49\pi cm^2.

Front

If a circle has a diameter of 10 m, what is its circumference rounded to the nearest tenth?

Back

C = \pi(10) \approx 31.4 m.

Front

What is the circumference of a circle with a diameter of 14 inches rounded to the nearest tenth?

Back

C = \pi(14) \approx 43.9 in.

Front

What is the value of \pi?

Back

\pi \approx 3.14.

Front

What is the relationship between radius and diameter?

Back

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