3. Angles

Explanation

An angle is formed when two lines or rays meet at a point. Different angles have different names based on their size. An acute angle is less than 90 

∘ a right angle is exactly 90 

∘and an obtuse angle is between 90 and 180 

 . A straight angle is 180 

 . The angles in a triangle always add up to 180 

∘ . Angles on a straight line also add up to 180