Law of Sines

1. Homework 11­4: Text p. 803‐804 #1‐4, 25, Worksheet 11‐4
1) 2) c=19.5
1)
2) 9.1 in2
3) 81.9 m2 3)
4)
25) a) 50o 4) 180 ­ 30 = 150o
b) 50o
c) 90o ­ a right angle
gives the Δ the
greatest height.

2. What is the point of this bunker?

3. Clues:
It's located near San Francisco.
It was built in 1942.
It's not for launching artillery or other weaponry!
You need two of them in different locations.
Advance the slide for the explanation from the
parks' service information kiosk...

5. 10.3
miles

6. Our problem is actually really hard to derive the formula from.
Let's look at a simpler problem, and then go back to it.
75o
x 12
67o 38o

7. The Law of Sines
used for finding either angles or sides.
To use the law of sines, an angle AND its opposite side
must be given!

8. =

10. 2. 20
13
A
Find m<A.

11. Classwork:
1. Find side c given
2. Find m<B:
20
B
25