Circles- Radius, Diameter, Circumference, and Area

Front

What is the distance from any point on the outside of a circle to the center of the circle called?

Back

Radius

Front

If the radius of a circle is 4 inches, what is the diameter?

Back

8 inches

Front

What is the formula for the circumference of a circle?

Back

Front

What is the distance across a circle through the center called?

Back

Diameter

Front

What is the space that a circle covers called?

Back

Area

Front

What is the formula for the area of a circle?

Back

Front

What is the relationship between radius and diameter?

Back

Front

What is the circumference of a circle with a diameter of 10 inches?

Back

@@C = ext{π}d = ext{π} imes 10 ext{ inches} \\ C ext{ is approximately } 31.4 ext{ inches}.$$

Front

If the circumference of a circle is 31.4 inches, what is the radius?

Back

@@r = rac{C}{2 ext{π}} = rac{31.4}{2 ext{π}} ext{ inches} \\ r ext{ is approximately } 5 ext{ inches}.$$

Front

What is the circumference of a circle with a radius of 5 inches?

Back

@@C = 2 ext{π}r = 2 ext{π} imes 5 ext{ inches} \\ C ext{ is approximately } 31.4 ext{ inches}.$$