Download Chapter 10.1

Opener
Use the diagram to answer the questions:
128°
x
75°
1. Solve for x.
y
2. Solve for y.
3. What information did you need to know to answer
question 2?
Chapter 10.1
Triangle sum,
exterior angle,
and
exterior angle
inequality theorems
Page 504
Skip problem 1, highlight the vocab term.
Problem 2.
What is an equiangular triangle?
1. Draw an acute triangle that is not an
equiangular triangle, and label the angles
with their measure. What are some possible
measures in the triangle?
Work on 1a in your groups…1 minute
Page 505
1b. The longest side of the triangle lies opposite
which interior angle?
The longest side of the triangle lies opposite the
largest interior angle.
1c. The shortest side of the triangle lies opposite
which interior angle?
The shortest side of the triangle lies opposite the
smallest interior angle.
Work on #2-5 in your groups…5 minutes
Page 508
Use the diagram to answer questions 1-11
1. Name the interior angles of the triangle.
The interior angles are <1, <2, <3
2. Name the exterior angles of the triangle
The exterior angle is <4
3. Skip
4. What does the m<1 + m<2 +m<3 equal? Explain.
m<1 + m<2 + m<3 = 180° because of the Triangle Sum
Theorem.
5. What does the m<3 + m<4 equal? Explain
m<3 + m<4 = 180 because they form a linear pair of
angles which measures 180°
Page 508…continued
6. Why does m<1 + m<2 = m<4? Explain.
If m<1 + m<2 +m<3, and m<3 + m<4 are both equal to
180, then:
m<1 + m<2 + m<3 = m<3 + m<4
Subtracting m<3 from both sides of the equation
results in: m<1 + m<2 = m<4.
Work on #7-11 in your groups…5 minutes
Page 510
Read for me please…
12. What can you conclude about the figure shown using
the Exterior Angle Theorem?
It can be concluded that the measure of <ACD is equal to
153°
13. What can you conclude about the figure shown using
the Exterior Angle Theorem?
It can be concluded that the measure of <ABC is equal to
127°
14. What can you conclude about the figure shown using
the Exterior Angle Theorem?
It can be concluded that the measure of <BAC is equal to
62°
Work on #15 in your groups…3 minutes
Page 512
Read for me please…
16. What can you conclude abut this figure using
the Exterior Angle Inequality Theorem?
It can be concluded that the measure of <ACD
is greater than the measure of <CAD and
greater than the measure of <ABC. Therefore
the measure of <CAD is greater than 19° and
the measure of <ACD is greater than 121°.
17. Skip
Work on your homework…