A half turn is 180° and is known as a straight angle (or angle on a straight line). A three-quarter turn is 270°. An acute angle is less than 90°. An obtuse angle is between 90° and 180°.

A line which cuts an angle into two equal side angles is called an angle bisector. In geometry a construction is an accurate drawing. There are two main constructions which can be done using a ...

Attach the two pieces with glue and screws at exact right angles to each other ... panels when you realize you need to draw a ...