Intro to Circles Flashcard

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

What is a tangent line?

Back

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

Front

What is the diameter of a circle?

Back

The diameter is a chord that passes through the center of the circle, and it is the longest chord.

Front

If segment AB is a chord, what can we say about its endpoints?

Back

The endpoints A and B lie on the circumference of the circle.

Front

How do you find the length of a chord given the radius and the distance from the center to the chord?

Back

Use the formula: length of chord = 2 * √(r² - d²), where r is the radius and d is the distance from the center to the chord.

Front

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

Back

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

Front

What is the formula for the circumference of a circle?

Back

Circumference = 2πr, where r is the radius.

Front

What is the area of a circle?

Back

Area = πr², where r is the radius.

Front

If TS is tangent to circle P, what can we infer about the angle formed with the radius?

Back

The angle formed between the tangent line TS and the radius at point P is 90 degrees.