More math help?

I am painting the walls and ceiling of a room. How many square meters am I painting if the room is 15 m long, 10 m wide, and 4.5 m high. Thank you.

L = 15m, W = 10m, H = 4.5m2 of the walls are L x H (2 x 15 x 4.5 = 135 sq m)2 of the walls are W x H (2 x 10 x 4.5 = 90 sq m)the ceiling is L x W (15 x 10 = 150 sq m)total 135 + 90 + 150 = 375 sq m