Reflex angle
How about reflex angles? This entry briefly looks at reflex angles. Reflex angles are angles greater than 180° and less than 360°. Below is an example of a reflex angle.
Monthly Archive: August 2013
Straight angle
Let us look very briefly at straight angles. A straight angle in geometry is an angle that measures exactly 180°. The angle is flat and is just a single straight line. An example of...
Obtuse angle
Let us look very briefly at obtuse angles. Below is an example of an obtuse angle. Obtuse angles are in a range between 90° and 180°. Any angle less or more is not an...
Right angle ∟
This type of angles is very popular or common in geometry. It is a very special angle and very easy to remember. The angle is so used it has it’s own computer character/symbol (∟)....
Acute angles
Here we shall look very briefly at acute angles. Among different types and sizes of angles is the acute angle. Acute angles smaller than a right angle (less than 90°) are called acute angles....
Addition formulae
This section explores using the addition formulae. You need to be able to use the addition formulae. Addition formulae explores trigonometric functions of sums of angles α ± β in terms of functions of...
Factor Formulae
This page explores factor formulae. The factor formulae can be used to express sums and differences of sines and cosines as products of sines and/or cosines. The factor formulae shown below are derived from...