Question

Construct a triangle ABC with sides 3 cm, 4 cm and 5 cm. Now, construct another triangle whose sides are `4/5` times the corresponding sides of ΔABC. 

Answer 1

Steps of construction:

1. Draw a line segment BC = 5 cm.
2. With B as a centre and radius 3 cm, draw an arc.
3. With C as a centre and radius 4 cm, draw another arc meeting the previous arc at the point A.
4. Join AB and AC to obtain ΔABC.
5. Below BC make an acute angle ∠CBX.
6. Along BC mark off five points B₁, B₂, B₃, B₄, B₅ such as BB₁ = B₁B₂ = B₂B₃ = B₃B₄ = B₄B₅.
7. Join B₅C.
8. From B₄ draw B₄C' || B₅C.
9. From C', draw CA' || CA meeting BA at the point A'.
   Hence, A' BC' is the required triangle.