Answer:
Explanation:
(A) From the given figure, it is given that ABC is a triangle and AC=6m, BC=7m and ∠C=83°.
thus, using the law of cosines in the given triangle ABC, we get

Substituting the given values, we have





Thus, option (C) is correct.
(B) From the given figure, it is given that ABC is a triangle and DE=6ft, DF=11ft and ∠D=40°.
thus, using the law of cosines in the given triangle ABC, we get

Substituting the given values, we have




