Hey, don't use < for an angle for if you put anything just to the
right of it it will delete it. Use 6 & # 8 7 3 6 ; (without the spaces) instead.
∠a = 2∠b = 6∠c
Get ∠a and ∠b in terms of ∠c
∠a = 6∠c <--- that's ∠a in terms of ∠c
2∠b = 6∠c
so
∠b = 3∠c <--- that's ∠b in terms of ∠c
Substitute in
∠a + ∠b + ∠c = 180°
6∠c + 3∠c + ∠c = 180°
10∠c = 180°
Divide both sides by 10
∠c = 18°
and since ∠b = 3∠c
∠b = 3(18°)
∠b = 54°
and since ∠a = 6∠c
∠a = 6(18°)
∠b = 108°
Edwin