Law of cosines
:
The law of cosines establishes:

general guidelines:
The law of cosines is used to find the missing parts of an oblique triangle (not rectangle) when either the two-sided measurements and the included angle measure are known (SAS) or the lengths of the three sides (SSS) are known.
Law of the sines:
In ΔABC is an oblique triangle with sides a, b, and c, then:

The law of the sines is the relation between the sides and angles of triangles not rectangles (obliques). It simply states that the ratio of the length of one side of a triangle to the sine of the angle opposite to that side is equal for all sides and angles in a given triangle.
General guidelines:
To use the law of the sines you need to know either two angles and one side of the triangle (AAS or ASA) or two sides and an opposite angle of one of them (SSA).
The ambiguous case
:
If two sides and an angle opposite one of them is given, three possibilities may occur.
(1) The triangle does not exist.
(2) Two different triangles exist.
(3) Exactly a triangle exists.
If we are given two sides and an included angle of a triangle or if we are given 3 sides of a triangle, we can not use the law of the sines because we can not establish any proportion where sufficient information is known. In these two cases we must use the law of cosines
Answer:
The equation is 
The value of x is 28 cookies
Step-by-step explanation:
Let
x ----> the number of cookies she baked last week
we know that
The number of cookies she baked last week multiplied by 3 minus 4 must be equal to 80 cookies
so
The linear equation that represent this situation is

solve for x

Answer:
C
Step-by-step explanation:
Answer:
Perimeter is irrational
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Step-by-step explanation:
<em>The attachment is missing but the question is still answerable</em>
Given

Required
Determine if the Perimeter is rational or not
First, we need to determine the sides of the square;

Substitute 


Take Square root of both sides


The perimeter of a square is calculated as:



<em>Because the value of </em><em>perimeter </em><em>can't be gotten by dividing two integers, then </em><em>perimeter is irrational</em>
Answer:
boiling and melting
Step-by-step explanation: