Question

4. Solve the triangle using either Law of Cosines or Law of Sines. In △DEF, f=25, e=8

and m∠F=131°.
Round your final answer to the nearest tenth. **

Angle D= Angle E= Angle d=

Answer 1

Explanation:

Using the Law of Cosines, we can find the remaining angle measures of the triangle.

Angle D = cos-1[(25^2 - 8^2 - (25^2 * cos(131°)))/(-2*8*25)] = 20.5°

Angle E = cos-1[(8^2 - 25^2 - (8^2 * cos(131°)))/(-2*25*8)] = 61.4°

Angle F = 180° - (20.5° + 61.4°) = 98.1°

Round to the nearest tenth:

Angle D = 20.5°

Angle E = 61.4°

Angle F = 98.1°