picture is painted cardboard 50cm long 30cm wide there is a margin 2.5cm along each side .find the total area of margin, class 7 solve measurements
Area of margin = Area of bigger rectangle including margin - Area of picture
Area of bigger rectangle = (50 + 2.5 + 2.5) * (30 + 2.5 + 2.5) = 55 * 35
Area of picture = 50 * 30
Area of margin = (55*35) - (50*30)