Brainlag PlusQuestions that need two or three facts in a row, with algebra, and a short proof.
One step, one reason
Most marks are lost by jumping.
Write each angle on its own line with its reason, then use it.
- angle AOB = 2 × 35 = 70° (the angle at the centre is twice the angle at the circumference)
- OA = OB (radii), so triangle OAB is isosceles
- angle OAB = (180 − 70) ÷ 2 = 55° (base angles of an isosceles triangle are equal)
The rest of this lesson and its 8 practice questions are in Plus.
Screen 1 of 4, free to read.
- 8 exam-style questions, marked as you go, each with a worked solution
- Anything you get wrong is saved to your flashcards