Measure down from the top the radius of the arc.
Find the center of the board.
Put a tape measure at an angle and find an even number. I used 8. Divide that in half and make a mark. I put a mark at 4. Make sure to mark on the correct side of the tape.
Draw a square line from the centerline across the line we drew for the radius. This is the center of the arc and hole.
Use a compass and set it on the center point and adjust the pencil straight out to the edge.
Draw your arc by using a sweeping motion.
Measure up from the bottom the correct distance according to the plans.
Use a straight edge to draw a line that is tangent to the circle and goes through the point we drew up from the bottom.
Tangent - A line that touches a circle that does not go through it. (Right on the edge of it.)
Draw extra practice lines on your project so you can figure out how to use the band saw.
Cut close to your line on the band saw.
Sand up to your line on the disc or belt sander with light pressure and stay in motion. (Perfect would be half way through your pencil mark.) Practice more as needed.