Question

Using the defects method, which relationship represents the Law of Cosines if the measure of the included angle between the sides a and b of ΔABC is less than 90°?

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

Answer 1

C !

Explanation:

Answer 2

Using the defects method, which relationship represents the Law of Cosines if the measure of the included angle between the sides a and b of ΔABC is less than 90°?

C) area of square c2 = area of square a2 + area of square b2 − area of defect1 − area of defect2

I'm really not familiar with this subject area but I have encountered this problem before and this answer was confirmed.