Given right triangle ABC, angle B=28 degrees, and side c=54.8in. Find side a.

We don't know which angle is the right angle

If it's C we have that

cos 28 = a / 54.8

Multiply both sides by 54.8

54.8 cos 28 = a ≈ 48.385

If A is the right angle, we have that

cos 28 = 54.8 / a rearrange as

a = 54.8 / cos 28 ≈ 62.06