Question

a picture is painted on a cardboard 8 cm long and 5 cm wide such that that margin of 1.5 CM along each of its sides find the total area of the margin

Answer 1

Hey there!

Given, Length of the cardboard = 8cm, Width of the cardboard = 5cm, Margin left along each side of cardboard = 1.5cm

Hence; Length of the cardboard without margin = 8cm — 1.5cm — 1.5cm = 5cm
Width of the cardboard without margin = 5cm — 1.5cm — 1.5cm = 2cm

Area of the cardboard = Length × Width 
= 8cm × 5cm = 40cm²

Area of the cardboard without margin = Length × Width 
= 5cm × 2cm = 10cm²

Therefore, Area of margin = Area of the cardboard — Area of the cardboard without margin
= 40cm² — 10cm²= 30cm²

Cheers!

Answer 2

Length (l) of cardboard = 8 cm

Breadth (b) of cardboard = 5 cm

Area of cardboard including margin = l × b = 8 × 5 = 40 cm2

From the figure, it can be observed that the new length and breadth of the cardboard, when margin is not included, are 5 cm and 2 cm respectively.

Area of the cardboard not including the margin = 5 × 2 = 10 cm2

Area of the margin = Area of cardboard including the margin − Area of cardboard not

including the margin

= 40 − 10 = 30 cm2