Chords, Tangents, & Secants

*You will not have to identify chords, secants, or tangents directly.*

and the 3 different formulas associated with them.

Intersection #1 - Angle formed ON the circle

When two 'lines' intersect ON a circle, we see a few important relationships.

1. The angles formed are a linear pair (add to 180º).

2. The two arcs formed add to 360º.

3. The intercepted arcs of each angle are DOUBLE the measure of the angle.

When two 'lines' intersect ON a circle, we see a few important relationships.

1. The angles formed are a linear pair (add to 180º).

2. The two arcs formed add to 360º.

3. The intercepted arcs of each angle are DOUBLE the measure of the angle.

When two 'lines' intersect ON a circle, we see a few important relationships.

1. The angles formed are a linear pair (add to 180º).

2. The two arcs formed add to 360º.

3. The intercepted arcs of each angle are DOUBLE the measure of the angle.

Intersection #2 - Angles formed INSIDE the circle

When two 'lines' intersect INSIDE a circle, we have a few important relationships:

1. The angles formed are sets of linear pairs (1 + 2 = 180º).

*Note the vertical angles formed)*

2. All four arcs formed add to 360º.

3. The intercepted arcs on either side of each angle are ADDED, then HALVED.

When two 'lines' intersect INSIDE a circle, we have a few important relationships:

1. The angles formed are sets of linear pairs (1 + 2 = 180º).

*Note the vertical angles formed)*

2. All four arcs formed add to 360º.

3. The intercepted arcs on either side of each angle are ADDED, then HALVED.

When two 'lines' intersect INSIDE a circle, we have a few important relationships:

1. The angles formed are sets of linear pairs (1 + 2 = 180º).

*Note the vertical angles formed)*

2. All four arcs formed add to 360º.

3. The intercepted arcs on either side of each angle are ADDED, then HALVED.