1. Bellringer 3. slope 1/3 , y-intercept 2 1. 4. 2. (2, 3), (1, 6)
Find the slope going through the points.
Use the given information to write an equation for each line.
3. slope 1/3 , y-intercept 2 4. 1.
2. (2, 3), (1, 6)

2. Parallel Lines and Triangles
Course: Geometry pre-IB
Quarter: 2nd
Objective: To use parallel lines to prove a theorem about triangles. To find measures of angles of triangles.
SSS: MA.912.G.2.2; MA.912.G.8.5

3. Classification by Sides
Equilateral Triangle
Isosceles Triangle
3 congruent sides
2 congruent sides
Scalene Triangle
No congruent sides

4. Classification by Angles
Acute Triangle
Equiangular Triangle
3 acute angles
3 congruent angles
Right Triangle
Obtuse Triangle
1 right angle
1 obtuse angle

5. Parallel Postulate
Through a point not on a line, there is one and only one line parallel to the given line. There is exactly one line through P parallel to m.

6. Triangle Angle-Sum Theorem
The sum of the measures of the angles of a triangle is 180.

7. Using the Triangle Angle-Sum Theorem
What are the values of x, y, and z?

8.  Solve for x, y, and z.

9. Solve for x.

10. Find the measure of angle A.

11. Angles in Triangles
An exterior angle is formed by a side and an extension of an adjacent side.
For each exterior angle of a triangle, the two nonadjacent interior angles are its remote interior angles.
Triangle Exterior Angle Theorem: The measure of each exterior angle of a triangle equals the sum of the measures of its two remote interior angles.
m1 = m2 + m3

12. Using the Triangle Exterior Angle Theorem
What is the measure of 1?
What is the measure of 2?

13. Find the measures of angles 1 and 2.

14. Find x and the angle measure.

15.  Two angles of a triangle measure 53
 Two angles of a triangle measure 53. What is the measure of an exterior angle at each vertex of the triangle?