Answer:
Step-by-step explanation:
1. 5 cm, 7 cm, 10 cm
SOLUTION: Â
The sum of the lengths of any two sides of a triangle
must be greater than the length of the third side.
5 + 7 > 10, 5 + 10 > 7, and 7 + 10 > 5
Thus, you can form a triangle with side lengths 5 cm,
7 cm, and 10 cm. Â
ANSWER: Â
Yes; 5 + 7 > 10, 5 + 10 > 7, and 7 + 10 > 5
2. 3 in., 4 in., 8 in.
ANSWER: Â
No;
3. 6 m, 14 m, 10 m
ANSWER: Â
Yes; 6 + 14 > 10, 6 + 10 > 14, and 10 + 14 > 6
4. MULTIPLE CHOICE If the measures of two
sides of a triangle are 5 yards and 9 yards, what is
the least possible measure of the third side if the
measure is an integer?
A 4 yd
B 5 yd
C 6 yd
D 14 yd
The correct option is B.
ANSWER: Â
B
PROOF Write a two-column proof.
5. Given:
Given:
Prove: YZ + ZW > XW
Proof:
Statements (Reasons)
1. Â (Given)
2. XW = YW (Def. of segments)
3. YZ + ZW > YW ( Inequal. Thm.)
4. YZ + ZW > XW (Substitution Property.)
ANSWER: Â
Given:
Prove: YZ + ZW > XW
Proof:
Statements (Reasons)
1. Â (Given)
2. XW = YW (Def. of segments)
3. YZ + ZW > YW ( Inequal. Thm.)
4. YZ + ZW > XW (Subst.)
Is it possible to form a triangle with the given
side lengths? If not, explain why not.
6. 4 ft, 9 ft, 15 ft
ANSWER: Â
No;
7. 11 mm, 21 mm, 16 mm
ANSWER: Â
Yes; 11 + 21 > 16, 11 + 16 > 21, and 16 + 21 > 11
8. 9.9 cm, 1.1 cm, 8.2 cm
No;
9. 2.1 in., 4.2 in., 7.9 in.
ANSWER: Â
No;
10. Â
No;
11. Â
ANSWER: Â
Yes;
Find the range for the measure of the third side
of a triangle given the measures of two sides.
12. 4 ft, 8 ft
ANSWER: Â
4 ft < n < 12 ft
13. 5 m, 11 m
ANSWER: Â
6 m < n < 16 m
14. 2.7 cm, 4.2 cm
ANSWER: Â
1.5 cm < n < 6.9 cm
15. 3.8 in., 9.2 in.
13.
ANSWER: Â
5.4 in. < n < 13 in.
16. Â
ANSWER: Â
17. Â
Â
ANSWER: Â
Proof:
Statements (Reasons)
1. Â (Given)
2. Â (Conv. Isos. Â Thm.)
3. BC = BD (Def. of  segments)
4. AB + AD > BD ( Inequal. Thm.)
5. AB + AD > BC (Subst.)
19. Given:
Prove: KJ +KL> LM Â
Proof:
Statements (Reasons)
1. Â (Given)
2. JL = LM (Def. of  segments)
3. KJ + KL > JL ( Inequality Thm.)
4. KJ + KL > LM (Substitution Property)
ANSWER: Â
Proof:
Statements (Reasons)
1. Â (Given)
2. JL = LM (Def. of  segments)
3. KJ + KL > JL ( Inequal. Thm.)
4. KJ + KL > LM (Subst.)
SENSE-MAKING Determine the possible
values of x.
20. Â
 Â
  Â
Notice that  is always true for any whole Â
number measure for x.The range of values that
would be true for the other two inequalities is
and  , which can be written as
.
ANSWER: Â
6 < x < 17
21. Â
ANSWER: Â
22. TRAVEL Keyan wants to take the most efficient
route from his hotel to the hockey game at The
Sportsplex. He can either take Highway 521 or
take Highway 3 and Route 11 from his hotel to the
arena.
a. Which of these two possible routes is the shorter?
Explain your reasoning.
b. Suppose Keyan always drives the speed l
Is it possible to form a triangle with the given
side lengths? If not, explain why not.
1. 5 cm, 7 cm, 10 cm
ANSWER: Â
Yes; 5 + 7 > 10, 5 + 10 > 7, and 7 + 10 > 5
2. 3 in., 4 in., 8 in.
ANSWER: Â
No;
3. 6 m, 14 m, 10 m
ANSWER: Â
Yes; 6 + 14 > 10, 6 + 10 > 14, and 10 + 14 > 6
4. MULTIPLE CHOICE If the measures of two
sides of a triangle are 5 yards and 9 yards, what is
the least possible measure of the third side if the
measure is an integer?
A 4 yd
B 5 yd
C 6 yd
D 14 yd
ANSWER: Â
B
Given:
Prove: YZ + ZW > XW
Proof:
Statements (Reasons)
1. Â (Given)
2. XW = YW (Def. of segments)
3. YZ + ZW > YW ( Inequal. Thm.)
4. YZ + ZW > XW (Subst.)
Is it possible to form a triangle with the given
side lengths? If not, explain why not.
6. 4 ft, 9 ft, 15 ft
ANSWER: Â
No;
7. 11 mm, 21 mm, 16 mm
SOLUTION: Â
ANSWER: Â
Yes; 11 + 21 > 16, 11 + 16 > 21, and 16 + 21 > 11
8. 9.9 cm, 1.1 cm, 8.2 cm
SOLUTION: Â
T
No;
9. 2.1 in., 4.2 in., 7.9 in.
No;
10. Â
ANSWER: Â
No;
11. Â
. Â
ANSWER: Â
Yes;
Find the range for the measure of the third side
of a triangle given the measures of two sides.
12. 4 ft, 8 ft
4 ft < n < 12 ft
13. 5 m, 11 m
6 m < n < 16 m
14. 2.7 cm, 4.2 cm
ANSWER: Â
1.5 cm < n < 6.9 cm
15. 3.8 in., 9.2 in.
13.
ANSWER: Â
5.4 in. < n < 13 in.
16. Â
 Â
Â
Proof:
Statements (Reasons)
1. Â (Given)
2. JL = LM (Def. of  segments)
3. KJ + KL > JL ( Inequal. Thm.)
4. KJ + KL > LM (Subst.)
SENSE-MAKING Determine the possible
values of x.
20. Â
SOLUTION: Â
Set up and solve each of the three triangle
inequalities.
 Â
  Â
ANSWER: Â
6 < x < 17
21. Â
Â
ANSWER: Â
Yes; 5 + 7 > 10, 5 + 10 > 7, and 7 + 10 > 5
2. 3 in., 4 in., 8 in.
ANSWER: Â
No;
3. 6 m, 14 m, 10 m
ANSWER: Â
Yes; 6 + 14 > 10, 6 + 10 > 14, and 10 + 14 > 6
4. MULTIPLE CHOICE If the measures of two
sides of a triangle are 5 yards and 9 yards, what is
the least possible measure of the third side if the
measure is an integer?
A 4 yd
B 5 yd
C 6 yd
D 14 yd
Â
The correct option is B.
ANSWER: Â
B
ANSWER: Â
No;
7. 11 mm, 21 mm, 16 mm
SOLUTION: Â
ANSWER: Â
Yes; 11 + 21 > 16, 11 + 16 > 21, and 16 + 21 > 11
8. 9.9 cm, 1.1 cm, 8.2 cm
Â
ANSWER: Â
No;
9. 2.1 in., 4.2 in., 7.9 in.