GEO #6 Circles A Circumference, Area, Equations

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

What is the area of a circle?

Back

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

Front

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

Back

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

Front

What is an inscribed angle in a circle?

Back

An inscribed angle is formed by two chords in a circle which have a common endpoint.

Front

What is the measure of an inscribed angle that intercepts a semicircle?

Back

The inscribed angle that intercepts a semicircle measures 90 degrees.

Front

What happens to the angles of a quadrilateral inscribed in a circle?

Back

The opposite angles of a cyclic quadrilateral are supplementary (add up to 180 degrees).

Front

What is a tangent to a circle?

Back

A tangent is a line that touches the circle at exactly one point.

Front

What is the point where a tangent intersects a circle called?

Back

The point of tangency.

Front

What is the relationship between two intersecting chords in a circle?

Back

The products of the lengths of the segments of each chord are equal.

Front

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

Back

A = (θ/360) × πr², where θ is the angle in degrees.