Transcript Document

WARM UP
Draw and label one of each of the following triangles:
(Be sure to include all necessary notations)
1. Obtuse
2. Scalene
3. Right
4. Isosceles
5. Acute
6. Equilateral
ACTIVITY: TRIANGLE SUM THEOREM
1. Get out a scratch piece of paper.
2. Using a ruler draw a large-ish triangle on your paper.
3. Cut out your triangle.
4. Tear two corners off the triangle.
5. Position the two torn-off corners next to the third angle as shown in the picture. Tape the two
corners in place.
6. Make a conjecture about the sum of the measures of the angles of a triangle and write it on
the back of your triangle.
7. Put the triangle with your name on it in your box on the back/side counter
NOTES
The Triangle Sum Theorem
The sum of the measures of the angles of a triangle is 180
The Parallel Postulate
Given a line and a point not on the line, there is one and only one
line that contains the given point and is parallel to the given line.
NOTES
Draw the picture below and then copy and complete the following table in your notes:
m1
m2
m1 + m2
m3
m4
30
70
30
80
110
70
110
40
80
120
60
120
40
90
130
50
130
NOTES
•
An angle such as 4 that forms a linear pair with an angle of a polygon is called an
exterior angle.
•
The angles of the polygon at the other vertices are called remote
of the exterior angle.
• In the diagram 1 and 2 are remote interior angles of 4.
interior angles
Exterior Angle Theorem
The measure of an exterior angle of a triangle is equal to the sum of the remote interior
angles.
WORKSHEET 
Complete the 3.5 Worksheet and then turn into your box
on the back/side counter.
Pick up a Project sheet once you are finished, read
through the project and begin brainstorming and
sketching your project design.
Check out homework on side board.