Angles, Triangles, Pythagoras Length, Area, Volume Numbers Fractions General Reference Sequences Expanding, Simplifying, Factorising Fun More Advanced Stuff Exam Review
A right angle is 90°.
An acute angle is an angle less than 90°. Angle a is an acute angle.
An obtuse angle is an angle more than 90° and less than 180°. Angle b is an obtuse angle.
A straight angle is a straight line, or 180°. Angle c is a straight angle.
A reflex angle is more than 180° and less than 360°.
Complementary angles sum to 90°.
In a right angle triangle the two acute angles are complementary because all three angles sum to 180°.
Supplementary angles sum to 180°.
Angles that sum to 360° are called explementary angles or conjugate angles. (These names are not part of the NCEA or IGCSE syllabuses.)
Home Astronomy Chemistry Electronics & Computers Mathematics Physics Field Trips Turn on javascript for email link
www.hometutoring.co.nz