Chords, Secants and Tangents

Definitions: 

Chord:
A chord is a segment that joins two points on a circle.
When a chord passes through a circle’s center, it is a diameter.

Secant:
A line that intersects a circle at exactly two points

Tangent:
A line that intersects a circle at exactly one point.

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Example: Determine if the figure depicts a chord, tangent or secanttang1_da02ab8f9928cf295c6d13e3fdc731f4.jpg-1341857748Solution:

Use the definitions of chord, secant and tangent along with the figure to decide which term is depicted.

Step 1: Analyze the figure. Here we are given a circle and a line. The line intersects with the circle at point P.

Step 2: Compare the figure to the vocabulary terms. Because the line intersects with the circle, we know it must be either a secant or tangent. Recall that a secant intersects with a circle at two points, while a tangent intersects with a circle at one point,

Because the line L intersects with the circle at only one point, we know the figure is depicting a tangent.

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