Steps of construction:
1) Draw a triangle PQR with sides PQ=QR=PR=6 cm.
2) Draw a rectangle ARCP with area equal to that of triangle PQR, by choosing length of rectangle as half of base and height same as height of triangle.
[ Here, area of rectangle = length × breadth
=1/2× base × height
= area of triangle]
Now, we can make a square with area equal to that of rectangle and hence equal to area of triangle.
3) Extend CP to CE, such that CE=BC
4) Draw the perpendicular bisector of PE which bisects PE at O.
5) Taking O as center and OD=OE as radius, draw a semicircle.
6) Extend BC which intersects semicircle at F.
7) Draw a square CFGH taking CF as side.
Here,
Area of square CFGH= area of rectangle ABCD
= area of △PQR