Respuesta :

Step-by-step explanation:

We are given that:

Circumference = 19.4 cm

Formula:

2πr = Circumference

Rewrite the equation:

  • ⇒ 2πr = Circumference = 19.4 cm
  • ⇒ 2πr = 19.4 cm

The "r" variable represents the radius of the circle. Thus, we need to isolate it on one side to determine the radius. This can be done with the four mathematical operations (+  -  ×  ÷). Since the "÷" is included, we can divide both sides by 2π to isolate the "r" variable.

Divide both sides by 2π:

  • ⇒ 2πr/2π = 19.4 cm/2π
  • ⇒ r = 9.7 cm/π

Substitute the radius as 22/7:

  • ⇒ r = 9.7 cm ÷ 22/7
  • ⇒ r = 9.7 cm x 7/22
  • ⇒ r = 67.9/22 cm