angles (find measure, given value of cosine)

[sarah.p]

im sorry i have so many questions

Find each angle measurement to the nearest tenth of a degree.

a) Angle B is obtuse and cos B = - 0.8371

33°

b)Angle D is obtuse and cos D = - cos 44.2°

0.72

 

[skeeter]

Re: angles

im sorry i have so many questions

Find each angle measurement to the nearest tenth of a degree.

a) Angle B is obtuse and cos B = - 0.8371

33° is this angle obtuse?

b)Angle D is obtuse and cos D = - cos 44.2°

D = cos^-1[-cos(44.2)] = 135.8

0.72

 

[sarah.p]

oh right!

can you tell me how to find the corect answer for the first part