HPreCalc Chapter 6 Part 1 Test

Question 1

What is the alternative form of the law of cosines

Answer 1

CosA=b^2+c^2-a^2/2bc

Question 2

Always use ______ decimals for problems with multiple steps

Answer 2

Unrounded

Question 3

Why can’t you use the law of sines to find an obtuse angle

What should you do to avoid making this mistake

Answer 3

Law of sines has a domain that will make the angle either right or acute
Use law of cosines to find biggest angle first

Question 4

When using Heron’s formula, look for __________ and __________

Answer 4

Perfect squares and repeated factors

Question 5

If you have 45 in Heron’s formula, separate it into __ and ___

Answer 5

9 and 5 (take out a 3)

Question 6

When finding a bearing in a triangle, start N or S. You can tell by seeing which one is closest to a ___ of that triangle

Answer 6

Side

Question 7

When you are given three sides of a triangle, you use the Law of ___ to find the three angles of the triangle

Answer 7

Cosines

Question 8

When you are given two angles and any side of a triangle, you use the law of ____ to solve the triangle

Answer 8

Sines

Question 9

The law of cosines can be used to establish a formula for finding the area of a triangle;e called _____ ______ formula

Answer 9

Heron’s Area

Question 10

When do you use law of cosines

Answer 10

SSS

SAS

Question 11

When do you use law of sines

Answer 11

ASA, AAS, SSA

Question 12

When is it not possible to use law of sines or law of cosines

Answer 12

AAA

Question 13

What is ambiguous case

Explain

Answer 13

SSA
There can (possibly) be two triangles or even no triangles.
Find the height and decide

Question 14

When you can make two triangles using ambiguous case, how do you find the second

Answer 14

Make the other angle its supplement (should be obtuse). Keep the two side lengths the same and solve

Question 15

Oblique means

Answer 15

Not right or isosceles

Question 16

What is the law of sines

Answer 16

A/sinA=B/sinB=C/sinC

Question 17

Always check that the largest ____ matches up with the largest ____-

Answer 17

Angle, side

Question 18

Obtuse oblique triangles can either have ___ or ___ triangles
How can you tell

Answer 18

One, no

The side opposite the largest angle must be the largest side

Question 19

What is the area of an oblique triangle

When can this equation be used

Answer 19

Area=1/2bcsinA

SAS

Question 20

An _____ triangle is a triangle that has no right angle

Answer 20

Oblique

Question 21

For triangle ABC, the law of sines is a/sinA=_______=c/sinC

Answer 21

B/sinB

Question 22

Two ____ and one ____ determine a unique triangle

Answer 22

Angles, side

Question 23

The area of an oblique triangle is 1/2bcsinA=1/2absinC=_______

Answer 23

1/2acsinB

Question 24

Given A=36 degrees and a=5

What is one possible combination for one solution, two solutions, and no solution

Answer 24

One solution- 5 is greater than or equal to b, b=5sin36
Two solutions- 5 is less than B and B is less than 5/sin36
No solution- b is greater than 5/sin36

Question 25

What is the law of cosines

Answer 25

A^2=b^2+c^2-2bccosA