The Polygonal Lasso tool is useful for making straight-edged selections
Polygonal Lasso tool in Photoshop
  1. Choose the Polygonal Lasso tool  (L).

  2. In the tool options bar, specify a selection option: New Selection, Add to Selection, Subtract from Selection, or Intersect with Selection.

  3. Position the Polygonal Lasso tool pointer in the canvas and click to set the starting point for your selection.

  4. Drag to draw a straight segment around the object you want to select. Click to set the end point of your first segment. Continue to draw subsequent segments until your object is fully selected.

  5. To close your selection boundary, bring the Polygonal Lasso tool pointer over the starting point and click.