LAW OF COSINES

Example 1: Solve the following….

B

A

C

14 ft8 ft

19 ft

Example 2: Solve the following….

5 cm 8 cm

12 cm

15 cm

115˚10 cm

Example 3: Solve the following….

Example 4: Solve the following….

18 ft

10.5 ft

46.5˚

Solve the following….

2.3 mi

Another….

211ft

Heron’s Formula

Ex 1. Find the area of the following triangle.

a = 43m b = 53m c = 72m

Ex 2. Find the Area of the Triangle

a =31 b = 52 m c = 28 m

361.8 m2

Solve the following:

17,452 ft2

One more….• Land in downtown Columbia is

valued at $20 a square foot. What is the value of a triangular lot with sides of lengths 112, 148, and 190 feet?

$165,554

Determine whether the Law of Sines or the Law of Cosines is needed to solve each of the triangles.

a.) A = 15o, B = 58o, c = 94

b.) a = 96, b = 43, A = 105o

c.) a = 24, b = 16, c = 29

d.) a = 15, c = 42, B = 49o

Law of Sines

Law of Sines

Law of Cosines

Law of Cosines

HOMEWORK

Pg. 423

#’s 1 – 33 oddBRING YOUR BOOK

TOMORROW!

Partner Problems

•pg. 423 #’s 2, 10, 18, 24, 28, 32, 34, 39, 41, 48

*Quiz Tomorrow