question 1)
I assume it asks about the circumference (of only the circle arc)
C=r*2*pi
r=2
-> C=4pi
1 Quarter only of the circle: C/4=pi=3.1
if it's the perimeter of the shape then you need to add the two 2in sides
C=3.1+2*2=7.1
2)
C=r*2*pi, but not a full circle, only semi-> divide by 2-> C=r*pi
r=30
C=30pi=94.2
3)
the radius of the semicircle is 6/2=3mm
semicircle C=r*pi=3pi
add the rectangle perimeter
3pi+2*3+6=12+3pi=21.4
4)
C=2r*pi
insert 2r=d=12
C=12pi=37.7
5)
C=2r*pi
r=10
C=20*pi~62.8
3 rotations of the wheel->
distance=C*3=188.4
