Circles Review #2 12/10

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

Define a chord in a circle.

Back

A chord is a line segment with both endpoints on the circle.

Front

What is the relationship between the central angle and the arc length in a circle?

Back

The arc length is directly proportional to the central angle.

Front

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

Back

The area increases by a factor of four.

Front

What is the formula for the area of a circle?

Back

A = πr², where A is the area and r is the radius.

Front

What is the measure of a right angle in degrees?

Back

90°.

Front

How do you find the measure of an inscribed angle in a circle?

Back

The measure of an inscribed angle is half the measure of the intercepted arc.

Front

What is the relationship between the angles formed by two intersecting chords?

Back

The measure of the angle is equal to half the sum of the measures of the arcs intercepted by the angle and its vertical angle.

Front

If m∠DHG = (11x – 36)° and m∠GHF = (x + 12)°, how do you find x?

Back

Set (11x - 36) = (x + 12) and solve for x.

Front

What is the formula for the length of an arc?

Back

Arc length = (θ/360) × 2πr, where θ is the central angle in degrees.