Question

Given the triangle below, which of the following equations correctlyrepresents the relationship between a, b, and c?B ВTriangle not drawn to scaleO A. 6? - g +c? - 2ab cos(90)O B. 2 - 82 + 62 - 2ac cos(904)O C. c? - 8 +02 - 2ab cos(909)O D. g? - $? + b2 - 2ac cos (904)

Answer 1

Given the triangle:

The relationship between a, b and c can be found using the cosine rule, that is,

`\begin{gathered} c^2=a^2+b^2-2ab\cos C \\ C=90^0\lbrack\text{right angle\rbrack} \\ \therefore c^2=a^2+b^2-2ab\cos (90^0) \\ or,\text{ }c^2=b^2+a^2-2ab\cos (90^0) \end{gathered}`

Therefore, the correct answer choice is option C