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:
48.1 m³ available, 2.5m³ not available
Step-by-step explanation:
Tan(X) = 4.5/(5.8+1.7)
Tan X = 3/5
Hypotenuse² = 3² + 5² = 34
Sin X = 3/sqrt(34)
X = 30.96
1/sinX = 1.7/SinY
Y = 61.003°
Third angle: 180 - X - Y = 88.037
Volume
= ½ × 1.7 × 1 × sin(88.038) × 3
= .
= 2.548
= 2.5m³
Available for storage:
½×4.5×7.5×3 - 2.548
= 48.077 = 48.1 m³
That is true because factors of 40 are 10,5
9 thirds, there a three thirds in each whole