How do you find the exact value of the third side given triangle ABCABC, a=62.5, b=44.7, mangleC=133a=62.5,b=44.7,mC=133?

1 Answer
Apr 17, 2017

Third side c=98.565c=98.565

Explanation:

We can use the cosine formula to find the length of a side or size of an angle. For a triangle with sides a,ba,b and cc and angles A, BA,B and CC the cosine rule can be written as c^2=a^2+b^2-2abcosAc2=a2+b22abcosA.

Here a=62.5a=62.5, b=44.7b=44.7 and m/_C=133°, hence

c^2=62.5^2+44.7^2-2×62.5×44.7×cos133°

= 3906.25+1998.09-125×44.7×(-0.682)

= 3906.25+1998.09+3810.675

= 9715.015

Hence c=sqrt9715.015=98.565