Answer:
y = 5.6
Step-by-step explanation:
Use Sine
Sine = 
Sine 45 = 
Sine of 18 is 0.309
0.309 =
Multiply 18 on both sides
0.309 x 18 = x 18
5.562 = y
Round to the nearest tenth:
5.562 = 5.6
Answer:
x=4
Step-by-step explanation:
1. isolate the variable by subtracting 7 on both sides: 4x=23-7
2. simplify: 4x=16
3. divide both sides by 4: x=16/4
4. simplify: x=4
Answer:
jerry 5% saves more than tom
Step-by-step explanation:
tom saves 35%
and jerry saves 40%
Answer:
The answer is B
you should still invest in a calculator (:
The area of a polygon is given by the formula Area = ap/2 where a is the length of the apothem and p is the perimeter. The apothem is a line from the center of the polygon perpendicular to a side.
Depending on the formula you know, you can find the length of a side in 1 of 2 ways.
The first way uses a triangle. Using the radius of the polygon you can create 8 congruent triangles. The center angle will be 360 / 8 = 45 and two side lengths of 20. You can find the length of the base using the law of cosines.
c^2 = 20^2 + 20^2 - 2(20)(20)(cos 45)
c^2 = 400 + 400 - 800(cos 45)
c^2 = 800 - 800(cos 45)
c = sqrt(800 - 800(cos 45)
c = 15.31
The second way is to use this formula:
r = s / (2 sin(180 / n))
20 = s / (2 sin(180/8)
(20)(2)sin(22.5) = s
(40)sin(22.5) = s
s = 15.31
We need to calculate the perimeter. As there are 8 sides (8)(15.31) = 122.48
Now we need to calculate the apothem using
a = S / (2 tan (180 / n)
a = 15.31 / (2 tan (180 / 8))
a = 18.48
Now solve for the area
Area = ap/2
Area = (18.48)(122.48)/2
Area = 1131.72
perimeter = 122.48
area = 1131.72
