Answer:
23.3
(or
(let me know if you wanted this one and is you want it explained) lol)
Step-by-step explanation:
To find the length of the fence, use the Pythagorean theorem because, if you cut a rectangle diagonally, you will create two right triangles, and this formula only works with right triangles:

Insert values:

Solve for c:
Evaluate exponents

Simplify addition

Find the square root of both
The fence needs to be approximately 23.3 m.
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:
Orginal Speed is 135
Step-by-step explanation:
The ratio of final speed: original speed is

We know that 90 km is it final speed so, we set up a proportion


If you have a graphing calculator just put in the equation in 'y=' (not the i equation), and then go to 2nd trace and see where the y=0, those numbers under the x column are the zeros. For the first one, the zeros are: -1, .5, and 2.8. For the second question the zeros are: -3 and about 1.9. The zeros with a decimal are estimations.