Answer:
x=42°
y=64°
z=68°
Explanation:
Consider the triangle towards the right with 90° and 48° marked. The other angles must equal 42° (angles in a triangle add to 180, 42+48+90=180). This 42° angle is vertically opposite x, so x=42°.
The triangle that contains z also contains the angle 22° and 90° (because it is on a straight line with another 90° angle and the angles along a straight line add up to 180 (90+90=180)). Since the angles in a triangle add to 180, z=68°. (68+22+90=180)
The angles z, 48° and y lie along a straight line. Since the angles along a straight line equal 180 and since we know that z=68°, we can say y=64° (68+64+48=180)