Question

question 6 of 25 select the angle that correctly completes the law of cosines for this triangle. 8² + 17² - 2(8)(17)cos ___ = 15² a. 90° b. 62° c. 180° d. 28°

Explanation:

Step1: Recall law of cosines formula

The law of cosines for a triangle with sides \(a\), \(b\), \(c\) and the angle \(\theta\) opposite to side \(c\) is \(c^{2}=a^{2}+b^{2}-2ab\cos\theta\). In the given equation \(8^{2}+17^{2}-2(8)(17)\cos\theta = 15^{2}\), the side opposite the angle \(\theta\) is 15.

Step2: Identify the angle

Looking at the triangle, the angle opposite the side of length 15 is 62°.

Answer:

B. 62°