Bell Ringer

Given the lengths of two sides of a triangle.Write an inequality to express the third side.

Example 1:7.8 cm, 13.2 cm

Example 2:9 in, 17.6 in

Example 3:2 in, 19 in

1A B

C

2

3

Comparisons“across from”

AC <2

AB <3

BC <1

Name the longest side and largest angle.

A

B C

1917

15

D

E

F

2818

21

G

H I

35°

65°

Opposite Side-Angle Theorem

- If one side of a triangle is longer than another side, then the angle opposite the longer side is larger than the angle opposite the shorter side.

Opposite Angle-Side Theorem

- If one angle of a triangle is larger than another angle, then the side opposite the larger angle is longer than the side opposite the smaller angle.

Practice

A

B C

m<A > m<B, so:

________________ Theorem

PracticeD

E

F

DF > EF, so:

________________ Theorem 1

2

3

Practice

G

H

I

GI > HI, so:

________________ Theorem

12

3

You try!

X

Y

Z

YZ > YX, so:

________________ Theorem 1

2

3

L

M

N

<1 > <2 EF, so:

________________ Theorem 1

2

3