AQA · Mathematics · 8300

GCSE Maths: Geometric Proof

Geometry & Measures · AQA GCSE Maths (8300). Cards are generated from the Corbettmaths video for Geometric Proof (Corbettmaths Video 366), and every card links back to the exact page it came from. Practice tests are drawn from this deck’s own cards. Source material © Corbettmaths — used with attribution.

12 flashcards · Free to study · No account needed

Study this deck

Preparing your cards…

All questions and answers

Read through the full deck, or practise recalling each answer above.

  1. In a geometric proof, what should you write down after each step?

    Show answer

    The reason for that step (e.g. "angles in a triangle add up to 180°"), so the marker can see clearly what was done.

  2. If CP = BP in triangle BCP, what type of triangle is it?

    Show answer

    Isosceles — two sides are equal, so the base angles BCP and CBP are equal.

  3. The angles in a triangle add up to ? degrees.

    Show answer

    180

  4. A triangle has angles 3x and x. What is the third angle?

    Show answer

    180° − 4x, because angles in a triangle sum to 180°.

  5. What does QED stand for at the end of a proof?

    Show answer

    Quod erat demonstrandum — Latin for "that which had to be demonstrated".

  6. Why is QED written at the end of a proof?

    Show answer

    To show the proof is finished — what was asked has been demonstrated.

  7. What construction helps prove angle facts for a point between two parallel lines?

    Show answer

    Draw a third line through the point, parallel to both given lines, so alternate angles can be used.

  8. What is the correct name for the angles informally called "Z angles"?

    Show answer

    Alternate angles (which are equal on parallel lines).

  9. Angles on a straight line add up to ? degrees.

    Show answer

    180

  10. Why are two radii of a circle useful for forming isosceles triangles?

    Show answer

    All radii of a circle are equal in length, so a triangle with two radii as sides is isosceles.

  11. An angle on a straight line is 180° − 2x. What is the adjacent angle?

    Show answer

    2x, because angles on a straight line sum to 180°.

  12. Three angles x, 180° − 4x and θ lie on a straight line. Find θ.

    Show answer

    θ = 3x, since x + (180° − 4x) + θ = 180°.

Want to create your own cards? Create a free account. AI generation uses credits.