Question

Using the defects method, which of these relationships represents the Law of Cosines if the measure of the included angle between the sides a and b of ∆ABC is more than 90°?

Answer 1

a. area of square c2 = -area of square a2 – area of square b2 + area of defect1 + area of defect2
b. area of square c2 = area of square a2 + area of square b2 + area of defect1 – area of defect2
c. area of square c2 = area of square a2 + area of square b2 – area of defect1 – area of defect2
d. area of square c2 = area of square a2 + area of square b2 + area of defect1+ area of defect2
e. area of square c2 = area of square a2 - area of square b2 + area of defect1 - area of defect2