Here, l = 4 m, b = 3 m, h = 2.5 m

The tarpaulin is needed to cover 5 faces only (excluding the floor)

Surface area of the shelter = lb + 2 (bh + hl)

= 4 × 3 m^{2} + 2(3 × 2.5 + 2.5 × 4) m^{2}

= 12 m^{2} + 2(7.5 + 10) m^{2} = (12 + 35) m^{2} = 47 m^{2}

Hence, 47 m^{2} of tarpaulin is required to make the shelter **Ans.**