Question

Construct a triangle whose perimeter is 12 cm and the ratio of their sides is 3:4:5.

Answer 1

It is given that AB: BC: CA = 3: 4: 5

3x + 4x + 5x = 12

12x = 12

x = 1

AB = 3 cm, BC = 4 cm and CA = 5 cm

Steps of construction:

(1) Draw a sufficiently long line segment using a ruler.

(2) Locate points A and B on it such that AB = 3 cm.

(3) With A as the centre and radius 5 cm, draw an arc.

(4) With B as the centre and radius 4 cm, draw another arc that cuts the previous arc at C.

(5) Join AC and BC.

Then, ABC is the required triangle.