There are two variations, the Angle tool and the Posture tool:
The Angle Tool allows you to draw an angle of any degree. Position the cursor at one of the endpoints of the angle. Click and draw the first leg of the angle toward the vertex (corner). Release the button and re-position the cursor at the other endpoint.Now when you click and draw, an angle measurement will appear. Release the mouse button to complete the angle.
The Posture Tool allows you to draw posture angles, which are comprised of three lines with angle measurements at the hip and knees. To draw a posture angle, click and draw a line from the shoulders to the hips. Then, click the knees and then finally the ankles.