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
Answer:
p=10
Step-by-step explanation:
3p+10+5p=90
8p+10=90
8p=80
p=10
Answer:
9
Step-by-step explanation:
listing the factors
27 : 1, 3, 9, 27
36 : 1, 2, 3, 4, 9, 12, 18, 36
the common factors are 1, 3, 9
the highest common factor is 9
The first odd number is 1. The next is 2 more than the previous one.
It's an arithmetic sequence.
The general term of an arithmetic sequence:
a_n - n-th term
a_1 - first term
d - common difference.
We have
Substitute:
<h3>Answer: 137th odd number is equal 273.</h3>
Answer:
Ok cool.
Step-by-step explanation:
