Find the measure of angle R and the measure of angle Q.

Question

anonymous · Answer

@amistre64 @thomaster @SithsAndGiggles

amistre64 · Answer

gonna have to get out my protractor eh .....

anonymous · Answer

attachment

amistre64 · Answer

law of cosines should work ....

anonymous · Answer

i know but i don't know how to use it...

amistre64 · Answer

solve for alpha ....

$$c^2 = a^2 + b^2 - 2ab\cos(\alpha)$$
$$c^2 - (a^2 + b^2) =  - 2ab\cos(\alpha)$$
$$\frac{a^2 + b^2- c^2 }{2ab} =\cos(\alpha)$$
$$\cos^{-1}\left(\frac{a^2 + b^2- c^2 }{2ab}\right) =\alpha$$

amistre64 · Answer

|dw:1400619237710:dw|

amistre64 · Answer

in other words:  a b are the legs adjecent to the angle;  and c is the one across from it

anonymous · Answer

$$\cos^{-1} (0.8) = \alpha$$
 = 36.87

anonymous · Answer

is that right?

amistre64 · Answer

gonna make me pull out the wolf instead .... fine \cos^{-1}(\frac{48^2 + 60^2- 36^2 }{2(48)(60)}) http://www.wolframalpha.com/input/?i=arccos%28%5Cfrac%7B48%5E2+%2B+60%5E2-+36%5E2+%7D%7B2%2848%29%2860%29%7D%29 36.87 degrees yes. good job :)

anonymous · Answer

haha thanks! can i ask you one more question? it's not related to this.

"Find all the missing parts to the triangle below."