2007-01-26 08:27:27 · 9 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
The only way I know of is to break it down into squares, rectangles and triangles.
Now if it's an exact pentagon there's a formula for that.
2007-01-26 08:35:53 · answer #1 · answered by Anonymous 7 · 0⤊ 0⤋
Area Of A 5 Sided Shape
2016-10-16 13:08:34 · answer #2 · answered by ? 4 · 0⤊ 0⤋
Depends on what shape it actually is, as there are lots of ways to draw a shape having 5 sides. But if the shape is convex (meaning all the corners point outwards), and every side is the same, then what you have is a regular pentagon, which is what the Pentagon building looks like from the sky.
Take a regular pentagon. Let "S" be the length of any side. Now draw a line from the center to each of the 5 corners, so that it looks something like the Dodge car logo. This splits the pentagon up into 5 identical triangles. Each triangle is an isoceles triangle, whose top angle is 360/5 = 72 degrees, and the bottom length is S. You can use some trig to find out that the height of this triangle is (s/2)*cot(36). This means the area of the triangle is (1/2)bh = (s/2) *(s/2)cot(36), or ((s^2)/4)cot(36).
There are 5 of these triangles, so the total area of the regular pentagon whose side length is S, is ((5s^2)/4)cot(36).
In general, you can use this process to find the area of any regular polygon: (ns^2/4)*cot(pi/n), where n = the number of sides.
2007-01-26 08:45:04 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Well, GT4lyfe, this is dependant. If you have a pentagon (which is most likely your problem), split it into triangles. If you know the length of the side (you should), split it half. Then you use the pythagorean theorom and find the length from the center of the circle to the middle of the line. Multiply this by the base and then divide it by two (if you didn't do this already). Once you find the are of one, simply multiply it by ten (five sides + divided by two = 10), and that should give you the total area.
Was that a help? =]
2007-01-26 08:59:28 · answer #4 · answered by mr_4dman 1 · 0⤊ 0⤋
If you are talking about a regular pentagon, then the area is equal to 1/2 the perimeter times the apothem, where the apothem is the distance from the center of the pentagon perpendicular to one of the sides. The perimeter is equal to 5 times the length of one side.
If yyou are talking about an irregular shaped oentagon, then you must break it into triangles as already suggested by one of the answerers.
2007-01-26 08:42:38 · answer #5 · answered by ironduke8159 7 · 0⤊ 0⤋
Break it up onto triangles. This works for finding the area of a shape with any number of sides.
2007-01-26 08:34:28 · answer #6 · answered by Ben B 4 · 0⤊ 0⤋
For a regular pentagon side length x:
Area=2.5x*0.5x*tan(54)
2007-01-26 08:47:19 · answer #7 · answered by Paul B 3 · 0⤊ 0⤋
It depends on it's actual shape.
i.e., a triangle and a cube perhaps
2007-01-26 08:34:39 · answer #8 · answered by Anonymous · 0⤊ 0⤋
regular or not?
divide it into triangles
2007-01-26 08:39:15 · answer #9 · answered by iyiogrenci 6 · 0⤊ 0⤋