Draw a triangle ABC with BC=6cm, AB=5cm and ∠ABC=60°. Then construct a triangle whose sides are 3/4 of the corresponding sides of the ΔABC.

The ΔA'BC' whose sides are 3/4 of the corresponding sides of ΔABC can be drawn as follows:
Step 1: Draw a ΔABC with side BC=6cm, AB=5cm, ∠ABC=60°
Step 2: Draw a ray BX making an acute angle with BC on the opposite side of vertex A.
Step 3: Locate 4 points, B1, B2, B3, B4 on line segment BX.
Step 4: Join B4C and draw a line through B3, parallel to B4C intersecting BC at C'.
Step 5: Draw a line through C' parallel to AC intersecting AB at A'.
The triangle A'BC' is the required triangle.