Tangents to Circles Review

Front

What is a tangent to a circle?

Back

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

Front

What is the point of tangency?

Back

The point of tangency is the point where a tangent line touches the circle.

Front

What is the relationship between a tangent and the radius at the point of tangency?

Back

A tangent to a circle is perpendicular to the radius drawn to the point of tangency.

Front

How many common tangents can two circles have?

Back

Two circles can have 0, 1, 2, or 3 common tangents depending on their positions.

Front

If two segments are tangent to a circle from a common external point, what can be said about their lengths?

Back

The lengths of the two tangent segments from a common external point to the points of tangency are equal.

Front

What is the formula for the length of a tangent segment from a point outside the circle?

Back

The length of the tangent segment can be found using the Pythagorean theorem: length = √(d^2 - r^2), where d is the distance from the point to the center of the circle and r is the radius.

Front

What is the perimeter of a shape formed by two tangents and two radii?

Back

The perimeter can be calculated by adding the lengths of the two tangent segments and the two radii.

Front

What is the significance of the angle formed between two tangents drawn from a point outside the circle?

Back

The angle formed between two tangents from a point outside the circle is equal to half the difference of the intercepted arcs.

Front

How do you find the length of a tangent segment if you know the radius and the distance from the external point to the center?

Back

Use the formula: length = √(d^2 - r^2), where d is the distance from the external point to the center and r is the radius.

Front

What is the relationship between the angles formed by two tangents to a circle?

Back

The angles formed by two tangents to a circle from a common external point are equal.