If the diameter of the heart is less than 2m, use 0.3 European pine board to expel the 3CM strip and use it to enclose the heart you want. Make the rest of the hearts according to the dome method. Draw a big circle outside the heart, draw a smaller concentric circle, and draw an arc. The rest shall be done according to the ring top method (it's hard to say on site). You should be able to figure it out yourself.