Draw a rectangle of perimeter 15 centimetres and sides in the ratio 3:4.

Method -1:

Given ratio of sides is 3:4.

Let one side be 3 , then other side would be 4

Therefore, total perimeter = 3 + 4 + 3 + 4 = 14

Here our perimeter is less than the required perimeter by 15-14 = 1

Step-1: using circle(centre B, radius BC) extend the base with side length (BC) as shown below

Step-2: take any slant line below base which will have a more length of 0.5cm than the base length(AE). ( here the extra length is half the difference between required perimeter and present perimeter)

Step-3: now join EG and draw a parallel line to EG through B. this meets AG at I.

Step-4: now take AI and IG as lengths of sides of required rectangle and form a rectangle as shown below:

Hence the bottom rectangle KJIA, is our required rectangle with perimeter 15.

Method-2:

Let ‘a’ and ‘b’ be the length and width of rectangle.

Then given

Then we know that perimeter will be 2(a + b)

Therefore, b = 4.286cm &