This presentation is the property of its rightful owner.
1 / 10

# EQ: What is the law of sines, and how can we use it to solve right triangles? PowerPoint PPT Presentation

EQ: What is the law of sines, and how can we use it to solve right triangles?. EQ: What is the law of sines, and how can we use it to solve right triangles?. The Law of Sines allows you to solve a triangle as long as you know either of the following:.

EQ: What is the law of sines, and how can we use it to solve right triangles?

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

#### Presentation Transcript

EQ: What is the law of sines, and how can we use it to solve right triangles?

EQ: What is the law of sines, and how can we use it to solve right triangles?

The Law of Sines allows you to solve a triangle as long as you know either of the following:

1. Two angle measures and any side length–angle-angle-side (AAS) or angle-side-angle (ASA) information

2. Two side lengths and the measure of an angle that is not between them–side-side-angle (SSA) information

EQ: What is the law of sines, and how can we use it to solve right triangles?

Using the Law of Sines for AAS and ASA

Solve the triangle. Round to the nearest tenth.

Step 1. Find the third angle measure.

mD + mE + mF = 180°

Triangle Sum Theorem.

Substitute 33° for mD and 28° for mF.

33° + mE + 28° = 180°

mE = 119°

Solve for mE.

sin F

sin D

sin F

sin E

=

=

d

e

f

f

sin 28°

sin 28°

sin 119°

sin 33°

=

=

e

d

15

15

15 sin 33°

15 sin 119°

d =

e =

sin 28°

sin 28°

d ≈ 17.4

e ≈ 27.9

EQ: What is the law of sines, and how can we use it to solve right triangles?

Step 2 Find the unknown side lengths.

Law of Sines.

Substitute.

Cross

multiply.

e sin 28° = 15 sin 119°

d sin 28° = 15 sin 33°

Solve for the

unknown side.

r

Q

EQ: What is the law of sines, and how can we use it to solve right triangles?

Using the Law of Sines for AAS and ASA

Solve the triangle. Round to the nearest tenth.

Step 1 Find the third angle measure.

Triangle Sum Theorem

mP = 180° – 36° – 39° = 105°

10 sin 36°

10 sin 39°

q=

r=

≈ 6.1

≈ 6.5

sin 105°

sin 105°

r

Q

sin Q

sin R

sin P

sin P

=

=

p

q

p

r

sin 39°

sin 36°

sin 105°

sin 105°

=

=

r

q

10

10

EQ: What is the law of sines, and how can we use it to solve right triangles?

Solve the triangle. Round to the nearest tenth.

Step 2 Find the unknown side lengths.

Law of Sines.

Substitute.

EQ: What is the law of sines, and how can we use it to solve right triangles?

Solve the triangle. Round to the nearest tenth.

Step 1 Find the third angle measure.

mH + mJ + mK = 180°

Substitute 42° for mH and 107° for mJ.

42° + 107° + mK = 180°

mK = 31°

Solve for mK.

sin J

sin H

sin H

sin K

=

=

h

k

h

j

sin 42°

sin 107°

sin 31°

sin 42°

=

=

k

h

8.4

12

12 sin 42°

8.4 sin 31°

h =

k =

sin 107°

sin 42°

h ≈ 8.4

k ≈ 6.5

EQ: What is the law of sines, and how can we use it to solve right triangles?

Step 2 Find the unknown side lengths.

Law of Sines.

Substitute.

Cross

multiply.

8.4 sin 31° = k sin 42°

h sin 107° = 12 sin 42°

Solve for the

unknown side.

EQ: What is the law of sines, and how can we use it to solve right triangles?

Solve the triangle. Round to the nearest tenth.

Step 1 Find the third angle measure.

Triangle Sum Theorem

mN = 180° – 56° – 106° = 18°

sin M

sin P

sin N

sin M

=

=

sin 56°

sin 106°

n

m

m

p

=

p

4.7

sin 106°

sin 18°

1.5 sin 106°

4.7 sin 56°

=

m=

p=

≈ 4.7

≈ 4.0

m

1.5

sin 18°

sin 106°

EQ: What is the law of sines, and how can we use it to solve right triangles?

Solve the triangle. Round to the nearest tenth.

Step 2 Find the unknown side lengths.

Law of Sines.

Substitute.