Perimeter Of Circle

perimeter of circle

perimeter of circle or circumference of the circle is defined as measurement of boundary length of the circle.

formula of circumference of the circle for radius R is 2piR,where R is radius of the circle and  value of π is 3.14 or 22/7. The circumference of the circle for diameter D is πD.




Question for practice

Q1. Find circumference of the circle whose radius is 4cm.

solution: Radius R=4cm

              circumference =2πR

                                    =2*3.14*4 = 25.12cm

Q2. Find circumference of circle where diameter is 16cm.

solution: Diameter D=16cm

              Radius R=16/2=8cm

            circumference=2πR

                                  =2*3.14*8=50.24 cm

Alternate Method : D=16cm

                              circumference=πD

                                                            =3.14*16=50.24cm

Q3. Find radius R where circumference is 50cm.

solution: C=50cm

              C=2πR

             50=2πR

             50/2=πR

              R=25/πcm


QUESTION FOR PRACTICE


Q1. Find the circumference of the circle whose radius is 12cm.

Q2. If circumference of circle is 176cm. Find radius R.

Q3. Find circumference where radius is 4.2cm.




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