From the question,
Length of the square flower bed = 2 m 80 cm = 2.8 m
It is extended by digging a strip = 30 cm = 0.3m
∴ Area of the square flower bed = (Side)2 = (2.80 m )2 = 7.84 m2
Side of the flower bed with the digging strip =(2.80 + 0.3 + 0.3) m = 3.4 m
Area of the enlarged flower bed with the digging strip = (Side )2 = (3.4 )2 = 11.56 m2
∴ Increase in the area of the flower bed = 11.56 m2 − 7.84 m2
= 3.72 m2