More Circle Vocabulary

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

There are 3 types of intersections that we will look at...

and the 3 different formulas associated with them.

Intersection #1 - Angle formed ON the circle

Intersection #1 - 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.

Intersection #1 - 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.

Intersection #1 - 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.

Example

Intersection #2 - Angles formed INSIDE the circle

Intersection #2 - 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.

Intersection #2 - 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.

Intersection #2 - 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.

Example