The problem states. There is a traingular plot of land, one side is 5 meters, one 10 meters, and one 7 meters. Find the Area. I believe that the law of cosines is used and then the area formule but im not sure. Can someone please tell me the answer and how to do the problem
2007-01-22 04:31:14 · 4 answers · asked by dude 1 in Science & Mathematics ➔ Mathematics
Solve for semiperimeter
a + b + c / 2
5 + 10 + 7 = 22/ 2 = 11
The semiperimeter is 11
Heron's Formula
a = √s(s - a)(s - b)(s - c)
a = √11(11 - 5)(11 - 10)(11 - 7)
a = √11(6)(1)(4)
a = √11(24)
a = √264
a = 16.24807681 meters
a = 16.25 meters rounded to two decimal places
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2007-01-22 05:51:02 · answer #1 · answered by SAMUEL D 7 · 0⤊ 0⤋
If p=(a+b+c)/2 half of the perimeter ,the area is
S =sqrt((p*(p-a)*(p-b)*(p-c))
in this case p= 22/2=11
S = sqrt ( 11*6*1*4)= 16.25 m^2
2007-01-22 12:54:48 · answer #2 · answered by santmann2002 7 · 0⤊ 0⤋
you know all the sides of the triangle so u do not need cosine all u need id da area = 1/2x basex height=half of 5 =2.5x 10=25
2007-01-22 14:23:27 · answer #3 · answered by birdie1990 2 · 0⤊ 0⤋
If you know the sides, and nothing more (no angles, for example), than you could use Heron's formula.
http://en.wikipedia.org/wiki/Heron's_formula
Knowing the formula makes everything else easy.
2007-01-22 12:42:34 · answer #4 · answered by Dan Lobos 2 · 1⤊ 0⤋