Homework Questions?
Jan 11­2:29 PM
Pop Quiz #2
Write down the exact values for the following:
1. sin 60
o
2. cos 60
o
3. tan 60
o
4. sin 45
o
5. tan 45
o
Jan 11­2:48 PM
1
Section 2.3 - significant figures and solving right triangles
Warm Up:
Find the number of significant figures in each of the following:
0.02
1.020
30
500
5001
40.
4.5
21.0
Significant figures
2 significant figures ­­ nearest degree
3 significant figures ­­ nearest 10' or 0.1
4 significant figures ­­ nearest 1' or 0.01
o
o
Oct 7­8:35 PM
Solving a right triangle means to find all missing sides and angles. Ex1:
How many significant figures should we use?
B= 9.5 o, a = 5.43 mi.
B
A =
B = 9.5
C = a = 5.43 mi
o
a
c
b =
c =
A
b
C
Jan 11­4:40 PM
2
Solve for all the missing parts of the following right triangles. o
Watch your significant figures. C = 90
1.
b = 377.3", c= 588.5"
B
a = 451.6", A = 50.12
B = 39.88
o
c
o
A
2.
B = 53 o 30', b = 725 mm
3.
A = 42 o, c = 89.70 ft
a
b
C
A = 36 o 30'
a = 536 mm
c = 902 mm
a = 60 ft
b = 67 ft
B = 48
o
Oct 7­8:47 PM
C
If AD is tangent to the circle and C is its center, what is the measure of CDA?
r
B
x
r
(x is the distance from A to B)
A
D
1.
2. If A = 31 o and r = 12, find If C = 26
o
and x = 2.1, find x.
r.
Oct 7­9:24 PM
3
Section 2.3 #62
A ferris wheel with a diameter of 165 feet was built in St. Louis in 1986. It is called Colossos. The top of the wheel stands 174 feet above the ground. Use the diagrams in this figure as a model of the Colossos.
Find h if θ is 150.0
o
θ
.
h
Oct 7­9:38 PM
4