Method 1:

Start by drawing a line with a length of 70 units. Divide this line into 6 equal segments. Use the midpoint of the line as the center to draw a circle, which will serve as the outer contour of the target shape.

For the first method, use the Arc-Start, End, Direction command to draw semi-circular arcs with the evenly spaced points as the endpoints. You can press the space bar to repeat the previous command and continuously draw all the necessary semi-circular arcs.

Add annotations to complete the drawing.

Method 2:

We will still start by drawing a line with a length of 70 units. Divide this line into 6 equal segments. Use the endpoints of the line to draw circles, which will serve as the outer contour of the target shape.

Using the evenly spaced points as endpoints, use the Arc-Start, End, Direction command to draw semi-circular arcs.

For this method, we will use the Scale command to duplicate and scale the semi-circular arcs. Repeat the Scale command with different scaling ratios to draw the upper half of the semi-circular arcs.

Then, we can use the method of rotating and copying to complete the lower half of these semi-circular arcs. During this process, don’t forget to input the letter “c” to confirm that the rotated lines are copied duplicates, so they won’t delete the previously completed upper half arcs.

Add annotations to complete the drawing.