Circles Review

Front

What is the formula for the circumference of a circle?

Back

C = 2πr, where C is the circumference and r is the radius.

Front

How do you find the radius if the circumference is given?

Back

Rearrange the formula: r = C / (2π).

Front

If the circumference of a circle is 12π, what is the radius?

Back

The radius is 6.

Front

What is an arc in a circle?

Back

An arc is a portion of the circumference of a circle.

Front

How do you measure an arc?

Back

The measure of an arc is the degree measure of the central angle that subtends the arc.

Front

If arc JKM measures 268 degrees, what does this represent?

Back

It represents the angle at the center of the circle that subtends arc JKM.

Front

What is the total degree measure of a circle?

Back

360 degrees.

Front

If arc SQ measures 95 degrees, what fraction of the circle does it represent?

Back

95/360 or 19/72 of the circle.

Front

What is the relationship between the central angle and the arc length?

Back

The arc length is proportional to the central angle.

Front

If the measure of arc ADC is 248 degrees, what is the measure of the remaining arc?

Back

The remaining arc measures 360 - 248 = 112 degrees.