(OL) Circles and Tangent Lines

Front

What is the radius of a circle?

Back

The radius of a circle is the measurement from the center of a circle to an edge of the circle.

Front

What is a tangent line?

Back

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

Front

What is the diameter of a circle?

Back

The diameter of a circle is the measurement from one edge of the circle to another edge through the center.

Front

If the radius of a circle is 3, what is the diameter?

Back

The diameter is 6, since the diameter is twice the radius.

Front

What is the relationship between radius and diameter?

Back

The diameter is twice the length of the radius.

Front

How do you find the circumference of a circle?

Back

The circumference can be found using the formula C = 2πr, where r is the radius.

Front

What is the formula for the area of a circle?

Back

The area of a circle is given by the formula A = πr², where r is the radius.

Front

If a circle has a diameter of 16, what is its radius?

Back

The radius is 8, since the radius is half of the diameter.

Front

What does it mean for lines AO and BO to be tangent?

Back

It means that both lines touch the circle at exactly one point each.

Front

If the measure of BO is 10, what can you infer about the length of AO?

Back

If AO is also tangent to the circle, then AO is also 10, as tangent segments from a point outside the circle are equal.