Question

Please help me ! please

Answer 1

`\sf {\large{4\pi }}`

Explanation:

Circumference of a circle ⭕ =
`2 \pi r`

Where,

r = d/2

d means diameter

r = 4/2 = 2

So, substitute to equation C = 2πr

C = 2πr

C = (2r)π

C = (2•2)π

C = 4π