Offset

Creates concentric circles, parallel lines and curves

Home tab > Modify panel > Offset

Specify offset distance: 100

Select object

Specify point on side

Pick any point inside the circle

Continue to select the line

Pick any point below the line

Multiple

Start the offset command

Specify offset distance: 200

Select the inner circle

Command line: Multiple

Continue to pick multiple points inside the circle

Through

Start Offset command

Command line: Through

Select a line

Snap through a point at the top of the circle by quadrant

Repeat the same steps to the bottom line

Layer

Set the current layer to Hidden

Start Offset command

Command line: Layer

Select Current

Press Enter fot the Through option

Select the top line

Snap to the quadrant of the 2nd circle

A hidden line offset below the top line

Repeat the command to offset the bottom line