Question

I don't know how to do anything. I basically need help with everything

Answer 1

Okay,

Radius, is half of the diameter.
Diameter, is the line that splits the circle in half.

1). R=50 D=100
2). R=10 D=20
3). R=5   D=10
4). R=29 D=58
5). R=11 D=22
6). R=31.5 D=63
7). R=45 D=90
8). R=7   D=14
9). R=49 D=98

 

Answer 2

For Diameter you either add the half (Radius) to itself

to get a radius (half from the middle) you divide the Diameter(the whole circle) by 2