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7/6/2017
Things to go over: Homework: p. 355, 1 – 24.
Problem o’ the Day
What are the measures of the acute angles of an isosceles
right triangle?
Correct
What
makes a number
What
makes aor
Right,
larger,
multiplication
again,
division
of smaller?
a number
number
multiplication!
greater than 1???
division!
The 45 - 45 - 90 Triangle
Divide by 2
Hypotenuse
To the shorter Side
45
x 2
x
45
x
Shorter Side
To the Hypotenuse
Multiply by 2
If the length of two congruent sides in a right
triangle are x, in terms of x, find the length of the
hypotenuse in simplest radical form.
p. 366
a.
9
45
h  9 2units
45
h
b.
x
45
2 2
x
45
2 2
2
x  2 units
45
x 2
x
45
x
p. 366, Check Understanding #1
Find the length of the hypotenuse of a 45º-45º-90º triangle with legs
of length 5 3
45
x 2
x
45
x
p. 367
Real-World
Connection
Softball A high school softball diamond is a square. The distance
from base to base is 60 ft. To the nearest foot, how far does a catcher
throw the ball from home plate to second base?
c  60 2 ft.
c  85 ft.
45
c
45
45
x 2
x
45
x
60 ft
60 ft
7/6/2017 Things to go over:
Problem o’ the Day
p. 367, Check Understanding # 1
A square garden has sides 100 ft long. You want to build a brick path
along a diagonal of the square. How long will the path be? Round
your answer to the nearest foot.
c  100 2 ft.
45
c
c  141 ft.
45
100 ft
100 ft
The 30 - 60 - 90 Triangle
30
2x
x 3
60
Divide by 3
x
30
Multiply by 2
2x
x 3
60
Multiply by 3
x
Divide by 2
p. 368
60
8
y
Find the value of each variable.
30
x
p. 368, Check Understanding #4
Find the lengths of the legs of a 30º-60º-90º triangle with hypotenuse of
length 12
p. 368
5
d
Find the value of each variable.
60
30
f
p. 368, Check Understanding #5
The shorter leg of a 30º –60º –90º triangle has length 6 . What are the
lengths of the other two sides? Leave your answers in simplest radical
form.
p. 368
Real-World
Connection
Road Signs A moose warning sign is an
equilateral triangle. Each side is 1 m long.
Find the area of the sign.
1m
h
60
0.5 m
0.5 m
p. 369, Check Understanding #6
6. A rhombus has 10-in. sides, two of which meet to form the
indicated angle. Find the area of the rhombus (Hint: Use a special
right triangle to find the height.)
a. a 30º angle
10 in.
30º
60º
b. a 60º angle
5 in.
10 in. 30º 5 3in.
10 in.
60º
5 in.
10 in.
Classwork:
p.369-370, #’s 1 - 23 odd.
Homework:
p.369-370, #’s 2 – 22
even.
Quiz in two days on Sections 7-1 to 7-3.