7) What is the primeter of scalene. Triangle having sides of 40mm, 20mm and 28mm?

8) What is the area of an equilateral triangle of side 450 mm?

9) What is the area of a circle of diameter 50 cm?

10) What is the area of a (A) semicircle whose dia is 20 cm (d)?

11) What is the cross sectional area of a circular ring of D = 38 mm d = 32mm?