I) Make a line AB of 7cm.
Make an right angle on A and draw an arc of 9cm from A to D.
Make an right angle on B and draw an arc of 9cm from B to C.
Then join D and C

ii)
Make a line AB of 12cm.
Make an angle of 45° on A and draw an arc of 13cm from A to C.
Make an right angle on B and then join it to C.
Measure the distance between B and C &Make an right angle on A and draw an arc of the same distance of C and B from A to D
Then join D and C​