Home Practice
For learners and parents For teachers and schools
Textbooks
Full catalogue
Leaderboards
Learners Leaderboard Classes/Grades Leaderboard Schools Leaderboard
Pricing Support
Help centre Contact us
Log in

We think you are located in United States. Is this correct?

Chapter summary

Test yourself now

High marks in science are the key to your success and future plans. Test yourself and learn more on Siyavula Practice.

Sign up and test yourself

10.9 Chapter summary

  • An arc is part of the circumference of a circle.
  • To bisect means to divide into two equal parts.
  • A perpendicular bisector is a line that intersects another line at right angles and divides the line into two equal parts.
  • We measure angles in degrees (\(^{\circ}\)). We use a protractor to measure an angle.
  • When the sum of two angles is equal to \(90^{\circ}\), we say that the two angles are complementary angles.
  • When the sum of two angles is equal to \(180^{\circ}\), we say that the two angles are supplementary angles.
  • The longest side of a triangle lies opposite the biggest angle of the triangle.
  • The shortest side of a triangle lies opposite the smallest angle of the triangle.
  • The sum of the lengths of the two shorter sides of the triangle must be greater than the length of the longest side of the triangle.
  • A scalene triangle has three angles of different sizes.
  • An isosceles triangle has two equal sides. It therefore also has two equal angles.
  • An equilateral triangle has three equal sides and three equal angles. Each angle is equal to \(60^{\circ}\).
  • The sum of the interior angles of a triangle is \(180^{\circ}\).
  • The sum of the interior angles of a quadrilateral is \(360^{\circ}\).
  • A square is a quadrilateral with all sides equal in length and all interior angles equal to \(90^{\circ}\).
  • A rectangle is a quadrilateral with opposite sides equal in length and all interior angles equal to \(90^{\circ}\).
  • A parallelogram is a quadrilateral with opposite sides equal and parallel.
  • A rhombus is a quadrilateral with opposite sides parallel and all sides equal in length.