Question

3. Two wire circles of diameters 28 cm and 35 cm are cut and then joined to form a big circle of radius
k cm. Find the value of k.​

Answer 1

Answer:

The radius, k , is 31.5 cm

Step-by-step explanation:

Find the circumference of the circle with diameter 28 cm:

Circumference = πD

                        = π(28)

                        = 28π cm

Find the circumference of the circle with diameter 35 cm:

Circumference = πD

                        = π(35)

                        = 35π cm

Find the Circumference of the big circle:

Total length = 28π + 35π

                  = 63π cm

Find the Diameter:

Diameter = Circumference ÷ π

               = 63π ÷ π

               = 63 cm

Find the radius:

Radius = Diameter ÷ 2

          = 63 ÷ 2

          = 31.5 cm