Before cutting down a tree, it’s necessary to learn how to identify a dangerous tree to avoid injury to yourself, bystanders, and your surroundings. Start by examining the angle of the tree.

When felling a tree, the rule of thumb is to make the depth of the notch one-fifth of the tree trunk’s diameter. The goal is to make the angles as shown in the diagram (or as close as you can).

Incorrect pruning, particularly “topping,” is the surest way to ruin a tree. If it doesn’t kill the tree outright, it will ...