+130555 Here's the way I'd do 3......
1. angle XUY = 180 XUY is a straight- angle
2. angle XUW + angle YUW = angle addtiton theorem
angle XUY
3. 90 + angle YUW = 180 substitution, angle XUW = angle 1 = 90
4. angle YUW = 180 - 90 subtract 90 from both sides of 3
5. angle YUW = 90 = angle 2 simplification of 4
+130555 Here's 4
1. angle 1 + angle 2 = 90 given, defintion of complementary
2. angle 3 + angle 2 = 90 given, definition of complementary
3. angle 1 + angle 2 = angle 3 + angle 2 equating 1, 2 with substitution
4. angle 1 = angle 3 subtract angle 2 from both sides of 3
+130555 Here's 5
1. angle 1 = angle 3 given
2. angle JOK = angle LOM given
3. angle JOK + angle KOL = angle KOL + angle LOM add angle KOL to each side of 2
4. angle JOL = angle KOM angle addition theorem
+130555 Here's 6
1. angle XUW = angle 1 = 90 given
2. angle XUY = 180 XUY is a straight angle = 180
3. angle XUY = angle YUW + angle XUW angle addition theorem
4. angle XUY - angle XUW = angle YUW subtract angle XUW from both sides of 3
5. 180 - 90 = angle YUW substituting 1 and 2 into 3
6. 180 = angle YUW + 90 add 90 to both sides of 4
7. 180 = angle 2 + 90 angle YUW = angle 2
