SOLUTION: a land 4 sides are 30,30,30,19.5 feets thn it's area is?

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Question 966918: a land 4 sides are 30,30,30,19.5 feets thn it's area is?
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
my best guess is the land is in the shape of a trapezoid.
the formula for the area of a trapezoid is 1/2 * (b1 + b2) * h.
b1 and b2 are the parallel bases.
h is the height.

do the bases have to be parallel to each other?
it doesn't state.

if the bases are parallel to each other, then the formula above will calculate the area.
if they are not, then i'm not sure how you would calculate the area except by using calculus or trigonometry or something like that since i don't believe there's a formula to calculate the area of an irregular shape that has the length of sides that you mention.

more information is needed.
are two of the sides parallel to each other?

if so, which sides are parallel to each other (could be two 30 foot sides or could be one 30 and one 19.5 side)?

if not, then more information is needed such as the angles at the corners of the piece of land.

assuming the land is in the shape of a trapezoid and assuming that the sides that are opposite to each other are the 30 foot and the 19.5 foot side, then the formula would be:

area = 1/2 * (19.5 + 30) * h

you would need to find h.
the trapezoid would have to be an isosceles trapezoid.
the height would be equal to 29.5370 feet.
the area would be eual to 731.04075 square feet.
round that to 2 decimal places and the area is 731.04 square feet.

the worksheet i used is shown below:

to find h, you need to drop perpendiculars from A and B to E and F.
this created right triangles.
you then used the left right triangle to find the value of h through the use of trigonometry.
the rest of the worksheet should be self explanatory.


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