Construct a whose perimeter is 12 cm and the lengths of whose sides are in the ratio 3:2:4.

According to the question, the sides are 3x, 2x and 4x.

Given perimeter = 12 cm

Therefore, 3x + 2x + 4x = 12

⇒ 9x = 12

⇒ x = 1.33 cm

Hence, the sides are 3.99 cm, 2.66 cm and 5.32 cm.

Steps of Construction:

1. Take AB = 5.32 cm and draw a line segment.

2. Measure 3.99 cm in ruler and draw an arc above AB from A. Again do the same for 2.66 cm but draw the arc from B.

3. Name the point where they intersect as C.

4. Join AC and BC.