Question

The cost of fencing a circular race course at the rate of rupees 8 per metre is rupees 2112. Find the diameter of the race course.

Answer 1

Answer:

diameter of circle is 84 meters

Step-by-step explanation:

The cost of fencing a circular race course at the rate of rupees 8 per meter

and total cost is rupees 2112

therefore,

perimeter of circle=total cost ÷rate of per meter

                              =2112÷8

perimeter of circle=264

but perimeter of circle=2πr

∴                             264=2πr

∴                                  r=264÷2π

∴                                  r=264÷2×22÷7

∴                                  r= 132×7÷22

∴                                  r=924÷22

∴                                  r=42

now diameter=2×r

                      =2×42

∴      diameter=84 meter

∴diameter of circle is 84 meter