What is the Exterior Angle Theorem?
The Exterior Angle Theorem states that the measure of an exterior angle of a triangle is equal to the sum of the measures of the two remote interior angles.
What is the Triangle Sum Theorem?
The Triangle Sum Theorem states that the sum of the angles in a triangle is always 180°.
What is the Angle-Angle Similarity Theorem?
The theorem states that if two angles of one triangle are equal to two angles of another triangle, then the triangles are similar.
What is a transversal?
A transversal is a line that crosses at least two other lines.
Find angle 8.

Angle 8= 65 degrees
How do you calculate the missing angle in a triangle?
To find an exterior angle, add the measures of the two non-adjacent interior angles of the triangle.
How do you calculate the missing angle in a triangle?
Subtract the sum of the two known angles from 180°.
How can you determine if two triangles are similar using angle measures?
If two angles of one triangle are equal to two angles of another triangle, the triangles are similar.
What are alternate interior angles?
Alternate interior angles are pairs of angles located on opposite sides of the transversal but inside the two lines.
Find angle 1.

Angle 1= 115 degrees
If one exterior angle is 120°, what are the measures of the remote interior angles?
The remote interior angles must sum to 120°
If two angles measure 45° and 55°, what is the measure of the third angle?
The third angle measures 80° (180° - 45° - 55° = 80°).
If two angles of a triangle measure 30° and 50°, what can you say about the third angle of another triangle?
The third angle must measure 100° if it corresponds to a triangle that is similar to this one.
How are corresponding angles related when a transversal crosses parallel lines?
Corresponding angles are equal when a transversal crosses two parallel lines
Find the missing angle.

Angle P= 85
Explain how the exterior angle relates to the interior angles.
The exterior angle is equal to the sum of the two opposite (remote) interior angles.
Explain why the Triangle Sum Theorem is true. (Think about the patty paper we ripped up)
If you take all the angles from a triangle and line them up so the angles are adjacent, they will form a straight line.
Explain what it means for triangles to be similar.
Similar triangles have the same shape but may differ in size; their corresponding angles are equal and their sides are proportional.
If two angles are supplementary, what can you say about their positions?
If two angles are supplementary and formed by a transversal crossing parallel lines, they are on the same side of the transversal and they add up to 180 degrees.
Find the missing angle.

Missing angle = 130 degrees
Provide an example with a diagram illustrating the Exterior Angle Theorem.

Solve for x.

x=96
Create an example involving two similar triangles with angle measures.
Provide a diagram and label all angle relationships formed by a transversal.

Find the missing angle.

Missing angle = 64 degrees.