Question

calculate the total surface area of the outside of an open box (without a lid ) which has a base measuring 1.0mby0.8m and has a height of 0.5m

Answer 1

here we can finnd it by 2 ways 
1. TSA-BASE AREA
2.LSA+BASE AREA 

im using 2nd one 

LSA OF A CUBOID= LBH(LENGTH×BREATH×HEIGHT)
100cm×80cm×50cm=400000cm²
base area = LB = 100CM×80cm=8000cm²
so LSA + BA =400000+8000=408000CM²
TO convert cm²to m²
=408000÷100×100=40.8m²