Why is a three-sided tree saw better?

Hello, I want to ask why the triangular tree saw is better. Three-sided tree saw will be better because the angle of sawtooth sharp angle is reduced, and it is more difficult to wear because of the existence of facet. The tooth tip of the three-sided tree saw also has a smaller plane, which is not the tooth shape of the common triangular tooth with double-sided grinding teeth, so the service life of the sawtooth is longer. Therefore, it is better to grind the tree saw on three sides, because the sharp angle of the sawtooth is reduced and the facet is more difficult to wear.