Didnt know what to put this under its sine and cosine

notsosmart25

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Sep 30, 2018
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A, B and C form the vertices of a triangle.
AB = 9cm, AC = 14cm and BC = 17cm.
Calculate the area of the triangle rounded to 1 DP.
 
This doesn't have much to do with sine and cosine, as far as I can see.

Are you aware of some standard methods for computing the area of a triangle? For example, maybe some equations that might apply?

Have you drawn a diagram of this problem?
 
You could use "Heron's formula: \(\displaystyle A= \sqrt{s(s- a)(s- b)(s- c)}\) where the a, b, and c are the lengths of the three sides and s is the "semi-perimeter", s= (a+ b+ c)/2. Here a= 17, b= 14, and c= 9. s= (a+ b+ c)/2= (17+ 14+ 9)/2= 40/2= 20. \(\displaystyle A= \sqrt{20(20- 17)(20- 14)(20- 9)]}\).
 
A, B and C form the vertices of a triangle.
AB = 9cm, AC = 14cm and BC = 17cm.
Calculate the area of the triangle rounded to 1 DP.

If you don't know (or even know about) Heron's formula, you could use the law of cosines to find an angle, then use the SAS formula for area of a triangle, which uses the sine of an angle and the adjacent sides.
 
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