1/ Draw a regular heptagon pol first. Like two straight lines in a picture, one end is the vertex of a regular heptagon and the other end is the midpoint of the opposite side. When scaling/referencing the size of 50,

2/ 3 points draw a circle, two points are the vertices of a regular heptagon, and the other point is the tangent point of a straight line.

3/ Array circle, polar axis array, and the number of array items is 7.

4/ Trim useless lines and draw a small circle in the middle with tangent/tangent/tangent circle.