Session 24Warmup

1
Session 24 Warm-up

• ? ABC has angles that measure 110, 50, and 20.
  Classify the triangle by its angles.
• ? RST has sides that measure 3 feet, 4 feet, and
  5 feet. Classify the triangle by its sides.
• ? KLM is an equilateral triangle in which
  KL 3x 2, LM x 8, and KM 2x 3.
  Find the measure of each side.

OBTUSE
SCALENE
13
2
Wed. 9/14 Quiz 5.5

• Warm-up
• Check Homework
• Notes 5.2 5.4
• Classwork
• Homework

Thurs. 9/15 5.6
Fri. 9/16 Review
Mon. 9/19 Test Ch 5
3
Go over HWp. 191 8-17
4
5.2 Angles of a Triangle
5
Theorem 5-1
Angle Sum Theorem The three angles in a
triangle add up to be 180º.
x y z 180
6
R
m ?R m ?S m ?T 180º
54
54º 67º m ?T 180º
121º m ?T 180º
67
S
T
m ?T 59º
7
m ? D m ?DCE m ?E 180º
E
55º 85º y 180º
B
y
140º y 180º
C
x
85
y 40º
55
D
A
8
Theorem 5-2
The acute angles of a right triangle
are complementary.
x y 90º
x
y
9
Find m?A and m?B in right triangle ABC.
m?A m? B 90
A
2x 3x 90
2x
5x 90
x 18
3x
C
B
m?A 2x
m?B 3x
2(18)
3(18)
54
36
10
Theorem 5-3
The measure of each angle of an equiangular
triangle is 60º.
x 60º
x
x
x
11
Find the value of each variable.
x
43
x
57
x 50º
12
Find the value of each variable.
55
43
(6x 7)
(40 y)
28
x 22º
y 57º
13
Find the value of each variable.
50
53
x
50
62
x 65º
14
Textbook p. 196 1 - 7
15
5-4 Congruent Triangles
Congruent triangles have congruent sides and
congruent angles. The parts of congruent
triangles that match are called corresponding
parts.
16
?RST is congruent to ?XYZ. Find the value of n.
Since ? RST is congruent to ?XYZ, the
corresponding parts are congruent.
60 2n10
50 2n
n 25
17
Complete each congruence statement.
B
DEF
C
A
D
F
E
18
Complete each congruence statement.
B
A
ECD
C
E
D
19
Complete each congruence statement.
GTK
T
G
K
H
20
Textbook p. 205 3-10
21
Work p. 196 8-20 even p. 206 12-24 even
Quiz next class!! 5.1, 5.2, 5.4