Answer: 3 metres³
Step-by-step explanation:
The shape described is that of a cuboid which means that the amount of concrete needed for the concrete base in cubic metres is the same as the volume of the cuboid/ concrete base.
Volume = Length * Width * Depth
All the units need to be in metres for the result to be in metres:
1 m = 100 cm
10 cm is therefore = 10/100 = 0.1 m
Volume = 6 * 5 * 0.1
= 3 metres³