In the figure (iii) given below, from a 24 cm × 24 cm piece of cardboard, a block in the shape of letter M is cut off. Find the area of the cardboard left over, all measurements are in centimetres.

From figure,

Area of rectangle (I) = length × breadth

= 24 × 6

= 144 cm².

Area of rectangle (II) = length × breadth

= 24 × 6

= 144 cm².

Area of parallelogram (III) = base × height

= 8 × 6

= 48 cm².

Area of parallelogram (IV) = base × height

= 8 × 6

= 48 cm².

Area of figure M = Area of rectangle (I) + Area of rectangle (II) + Area of parallelogram (III) + Area of parallelogram (IV)

= 144 + 144 + 48 + 48

= 384 cm².

Area of cardboard = 24 × 24

= 576 cm².

Area of cardboard left = Area of cardboard - Area of figure M

= 576 - 384

= 192 cm².

Hence, area of cardboard left = 192 cm².