Angles are gauges used to check right angles. An angle gauge is a measuring tool or structural element that has an 'L' shape. Its main uses are: Measurement of right angles: The angle iron is used to check that angles are right (90 degrees). This is particularly useful in carpentry, masonry and other crafts where precise angles are crucial. Drawing straight lines and angles: The angle iron helps to draw straight lines and determine right angles on various work surfaces. Checking straightness: Can be used to check the straightness of the edges of objects or materials.