Ex9-3 The area of a plan of an old map plotted to a scale of 10m to 1cm measures 100.2 square cm as measured by a planimeter. The plan is found to have shrunk so that a line originally 10 cm long measures 9.7cm. Further, the 20m tape used was 8cm too short. Find the true area of survey.
Solution : Given, the scale of the map = 1cm to10 m = 1: 1000
Present area of the plan, Ap= 100.2 cm2
Designated length of the tape , l = 20m
Actual length of the tape , l ' = 20m -8cm = 19.92 m
Since, originally 10 cm long measures 9.7cm,
