how is 2*pi*x the answer for this?

[unkempt smelt]

i was doing math today and saw this question, it wants me to find the perimeter and i dont get how 2 x pi*x is the answer

[light locust]

Because the perimeter is just the perimeter of two circles

[chrome vine]

4 semi-circles = 2 circles
so 2 * (pi * x)

[unkempt smelt]

But that's the formula for the circumference for 1 circle

So wouldn't it be 4 pi x

[humble seal]

P = 4L(semicirle) = 2L(circle) = 2πd(circle) = 2πx

[chrome vine]

no cuz here x is diameter not radius
C = 2pi(r) = pi(d)

[unkempt smelt]

ohhh

thx bro

but what about the square so wouldnt it be 2pi*x + x^2?

and for the area wouldnt it be 2 * pi * x^2?