Unit 9 Circles: Arcs, Angles, & Segments

Front

What is a tangent to a circle?

Back

A tangent to a circle is a line, ray, or segment in the plane of the circle that intersects the circle in exactly one point.

Front

What is a secant?

Back

A secant is a line, ray, or segment that intersects a circle at two points.

Front

What is the radius of a circle?

Back

The radius of a circle is a line segment from the center of the circle to any point on the circle.

Front

What is an arc in a circle?

Back

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

Front

If the radius of a circle is 5 cm, what is the diameter?

Back

The diameter is 10 cm (diameter = 2 x radius).

Front

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

Back

The arc length is directly proportional to the central angle in a circle.

Front

Calculate the circumference of a circle with a radius of 7 cm.

Back

Circumference = 2πr = 2π(7) ≈ 43.98 cm.

Front

What is the formula for the area of a circle?

Back

Area = πr².

Front

If the measure of an inscribed angle is 30 degrees, what is the measure of the intercepted arc?

Back

The measure of the intercepted arc is 60 degrees (twice the inscribed angle).

Front

What is the angle formed by two tangents drawn from a point outside the circle?

Back

The angle formed is equal to half the difference of the measures of the intercepted arcs.