# HPreCalc Chapter 6 Part 1 Test Flashcards Preview

## Junior Year > HPreCalc Chapter 6 Part 1 Test > Flashcards

Flashcards in HPreCalc Chapter 6 Part 1 Test Deck (25)
1
Q

What is the alternative form of the law of cosines

A

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

2
Q

Always use ______ decimals for problems with multiple steps

A

Unrounded

3
Q

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

What should you do to avoid making this mistake

A

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

4
Q

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

A

Perfect squares and repeated factors

5
Q

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

A

9 and 5 (take out a 3)

6
Q

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

A

Side

7
Q

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

A

Cosines

8
Q

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

A

Sines

9
Q

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

A

Heron’s Area

10
Q

When do you use law of cosines

A

SSS

SAS

11
Q

When do you use law of sines

A

ASA, AAS, SSA

12
Q

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

A

AAA

13
Q

What is ambiguous case

Explain

A

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

14
Q

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

A

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

15
Q

Oblique means

A

Not right or isosceles

16
Q

What is the law of sines

A

A/sinA=B/sinB=C/sinC

17
Q

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

A

Angle, side

18
Q

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

A

One, no

The side opposite the largest angle must be the largest side

19
Q

What is the area of an oblique triangle

When can this equation be used

A

Area=1/2bcsinA

SAS

20
Q

An _____ triangle is a triangle that has no right angle

A

Oblique

21
Q

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

A

B/sinB

22
Q

Two ____ and one ____ determine a unique triangle

A

Angles, side

23
Q

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

A

1/2acsinB

24
Q

Given A=36 degrees and a=5

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

A

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

25
Q

What is the law of cosines

A

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