Answer:
1) x=58, y=109
2) x=72, y=36
3) x=60, y=48
Step-by-step explanation:
1) 58 and x are so-called "F-angles" (a.k.a "corresponding angles), so x=58°
The angle on the other side of the 58 is 180-58 = 122 because they are supplementary. We need this one to calculate y.
The sum of angles in a quadrilateral is 360°, so 71 + 58 + 122 + y = 360, so y = 109
2) There are two isosceles triangles. Due to the symmetry, the bottom left angle is also 72, leaving 180-72-72 = 36 for y. The top triangle is the same triangle rotated, so x = 72.
3) Due to the parallel lines, the left angle of the top triangle is also 72, making the supplementary angle below it 180-72=108. The sum in the quadrilateral must be 360, so 72+108+2x+x=360, so 3x=180, x=60.
The sum in the outer triangle must be 180, so 72+y+x = 180, leaving y = 180-72-60 = 48
