Tangent Lines and Circles

Front

What is a diameter in a circle?

Back

A diameter is a chord that passes through the center of the circle, dividing it into two equal halves.

Front

How many points does a tangent line intersect a circle?

Back

A tangent line intersects a circle in exactly one point.

Front

What is a tangent line?

Back

A tangent line is a straight line that touches a circle at exactly one point without crossing it.

Front

What is a chord in a circle?

Back

A chord is a line segment whose endpoints lie on the circle.

Front

What is a secant line?

Back

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

Front

If a line is tangent to a circle, what can be said about the radius at the point of tangency?

Back

The radius drawn to the point of tangency is perpendicular to the tangent line.

Front

What is the relationship between a tangent line and a circle?

Back

A tangent line touches the circle at one point and does not enter the circle.

Front

How do you identify a tangent line in a diagram?

Back

A tangent line will appear to touch the circle at only one point, without crossing into the circle.

Front

What is the length of a tangent segment from a point outside the circle to the point of tangency?

Back

The length of the tangent segment is equal to the distance from the external point to the point of tangency.

Front

What is the formula for the length of a tangent segment?

Back

If a point P is outside a circle with center O and radius r, and the tangent segment is PT, then PT = √(OP² - r²).