Find the circumference

Please help

area = 147 cm²

circumference = 42 cm

Explanation:

area of a circle = r²

area = 3 × 7²

= 49 × 3

= 147 cm²

circumference of a circle = 2 r

circumference = 2 × 3 × 7

= 42 cm

map scale refers to the relationship (or ratio) between distance on a map and the corresponding distance on the ground. for example, on a 1: 100000 scale map, 1cm on the map equals 1km on the ground.