What is cosa for this triangle?

48/55

55/73

55/48

48/73

For this case we must indicate the cosine of A, of the figure shown. By definition:

Substituting the values we have:

So, we have to:

Option D

the sum of all the angles in a triangle are equal to 180

so you can add   the 3 given angles together to equal 180:

5y + 2y + 2y = 180

or since all three angles have the same letter, combine the 3 angles to equal 180:

9y = 180

(23*2)-12=x     x=34

step-by-step explanation: