Question

my exams are starting from next week i am facing so much problems in perimeter and area of simple geometrical figures . my question is ;find the area , in square centimetres , of a rectangular strip of board 3.28 m long and 75 mm wide . the second question is ; a square cardboard of side 1.2 m has a 10 cm wide border round the exterior of three of its sides . find the area of the border. if you don't mind can you solve the question which i asked so i can solve the rest of the question easily.

Answer 1

for any rectangle, the area is length * width.

So, get out your calculator and punch in your numbers.

watch out for the units. you can't mix <u>m</u> and <u>cm</u>.

For the cardboard with the border, the whole thing with border on 4 sides has area (120+10+10)^2 = 19600 cm^2
The inside cardboard has area 14400 cm^2
So, a full 4-sided border would have area 5200 cm^2. But, you only have a border on 3 sides, so you need to subtract 1/4 of that, leaving 3900 cm^2.
But that includes a little 10x10 corner, so lop off that 100 cm^2 leaving 3800 cm^2 of border.

Answer 2

425cm.sq