61^2=29^2+50^2-2(29)(50)cos x
Solving for cosx we have
[ 61^2 - 29^2 - 50^2 ] / [ -2 * 29 * 50 ] = cos x
Using the cosine inverse, we have
arccos ( [ 61^2 - 29^2 - 50^2 ] / [ -2 * 29 * 50 ] ) = x ≈ 97.53°
