The angles in a triangle add to equal 180°, so subtract 180°-55°-58° and 180°-64°-61° for the missing values of ∠WYX and ∠YXZ, respectively: ∠WYX = 67°, ∠YXZ = 55°.
The longest side of a triangle is opposite the largest angle, and the shortest side of a triangle is opposite the smallest angle:
In the triangle on the left, the shortest side must be XY because it is opposite the smallest angle, ∠W; the longest side is WX, which is opposite the largest angle, ∠WYX (67°).
In the triangle on the right, the shortest side is YZ, opposite the smallest angle, ∠YXZ (55°); the longest side is XZ, opposite the largest angle, ∠XYZ (64°)
