Geometry Circles Unit 4a Review

Front

What is the formula for the area of a circle?

Back

Area = πr², where r is the radius of the circle.

Front

What is the relationship between the diameter and radius of a circle?

Back

The diameter is twice the radius (d = 2r).

Front

How do you calculate the circumference of a circle?

Back

Circumference = πd or Circumference = 2πr.

Front

What is the measure of a full circle in degrees?

Back

A full circle measures 360 degrees.

Front

What is an arc in a circle?

Back

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

Front

What is the central angle of a circle?

Back

A central angle is an angle whose vertex is at the center of the circle and whose sides intersect the circle.

Front

How do you find the measure of an inscribed angle?

Back

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

Front

What is the formula for the area of a sector of a circle?

Back

Area of sector = (θ/360) × πr², where θ is the central angle in degrees.

Front

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

Back

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

Front

What is the formula for the length of an arc?

Back

Length of arc = (θ/360) × 2πr, where θ is the central angle in degrees.