Circle Review (Formulas)

Front

What is the formula for the circumference of a circle?

Back

C = 2πr, where r is the radius.

Tags

CCSS.7.G.B.4

Front

What is the formula for the area of a circle?

Back

A = πr², where r is the radius.

Tags

CCSS.7.G.B.4

Front

What is a secant in relation to a circle?

Back

A secant is a line that intersects a circle at two points.

Front

What is a tangent in relation to a circle?

Back

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

Front

How do you find the measure of an angle formed by two secants intersecting outside a circle?

Back

The measure of the angle is half the difference of the measures of the intercepted arcs.

Tags

CCSS.HSG.C.A.2

Front

How do you find the measure of an angle formed by a tangent and a secant?

Back

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

Tags

CCSS.HSG.C.A.2

Front

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

Back

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

Front

What is the formula for arc length?

Back

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

Tags

CCSS.HSG.C.B.5

Front

How do you determine if a point is inside, outside, or on a circle?

Back

Compare the distance from the point to the center with the radius. If distance < radius, inside; if distance = radius, on; if distance > radius, outside.

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.

Tags

CCSS.HSG.C.B.5