Construct a triangle ABC whose peimeter is 14cm and sides are in the ratio 2:3:4

Draw a line AB of 14 cm

Then divide it into 9 equal parts. Since 2+3+4=9

Then name the parts as 1,2,3,4,5,6,7,8,9.

Then from 2 with draw a semicircle with radius A2 and similarly from 5 of radius 5B

Name the intersection point of two circle as C

Now join AC and BC

So ABC is the required triangle