Explanation:
1 and 3 are complimentary angles, meaning 1+3 = 180 degrees.
in the same way 1 and 2 are complimentary angles, 1+2 = 180, => 2 ≈ 3
and for 2 and 4 the same => 1 ≈ 4
3 and 5 are complimentary angles, 3+5 = 180 degrees, => 1 ≈ 5.
7 and 8 are complimentary angles, 7+8 = 180 degrees, => (given that 1 ≈ 7 and therefore ≈ 4) 8 ≈ 2 ≈ 3
6 and 8 are complimentary angles, 6+8 = 180 degrees, => 6 ≈ 7 ≈ 1
and with 1≈5 and 1≈6 we know 5≈6.