Section 7.3 Triangles 287 Tell whether x and y show direct variation. Explain your reasoning. If so fi nd the constant of proportionality. (Section…

Section 7.3 Triangles
287
Tell whether x and y show direct variation. Explain your reasoning.
If so fi nd the constant of proportionality.
(Section 5.6)
28.
x = 2y
29.
y x = 6
30.
xy = 5
31.
MULTIPLE CHOICE A savings account earns 6% simple interest per year. The
principal is $800. What is the balance after 18 months?
(Section 6.7)

A
$864

B
$872

C
$1664

D
$7200
Draw a triangle with the given angle measures. Then classify the triangle.
14.
15 75 90
15.
20 60 100
16.
30 30 120
Draw a triangle with the given description.
17.
a triangle with a 2-inch side and a 3-inch side that meet at a 40 angle
18.
a triangle with a 45 angle connected to a 60 angle by an 8-centimeter side
19.
an acute scalene triangle
20. LOGIC You are constructing a triangle. You draw
90
90
80
100
70
110
60
120
50
130
40
140
30
150
20
160
10
170
0
180
100
80
110
70
120
6
0
13
0
5
0
140
40
150
30
160
20
170
10
180
0
35
the fi rst angle as shown. Your friend says that you
must be constructing an acute triangle. Is your
friend correct? Explain your reasoning.
Determine whether you can construct many one or no triangle(s)
with the given description. Explain your reasoning.
21.
a triangle with angle measures of 50 70 and 100
22.
a triangle with one angle measure of 60 and one 4-centimeter side
23.
a scalene triangle with a 3-centimeter side and a 7-centimeter side
24.
an isosceles triangle with two 4-inch sides that meet at an 80 angle
25.
an isosceles triangle with two 2-inch sides and one 5-inch side
26.
a right triangle with three congruent sides
27.
Consider the three isosceles triangles.
x
50
65
130
25
x
45
x
a.
Find the value of x for each triangle.
b.
What do you notice about the angle measures of each triangle?
c.
Write a rule about the angle measures of an isosceles triangle.
22
33
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