GCSE · Angles & polygons

Angle rules & giving reasonsExam-style questions

Why angles at a point make 360°, angles on a straight line make 180°, and vertically opposite angles are equal; the triangle and quadrilateral angle sums; isosceles triangles; and how to write the reasons examiners insist on.

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12 questions · GCSE (Higher) level · mark scheme and worked solution on each · no sign-up to try

DifficultyAll Level 2 Level 3 Level 4 Level 5

1
The angles of a triangle are $2x°$ , $(3x + 10)°$ and $(x + 20)°$ .

Work out the size of the largest angle. (3 marks)
Level 2 · 3 marksTry it
2
$ABC$ is a triangle with $AB = AC$ .

$BC$ is extended to the point $D$ .

Angle $BAC = 44°$ .Diagram NOT accurately drawn

Work out the size of the angle marked $x$ .

Give a reason for each stage of your working. (3 marks)
Level 2 · 3 marksTry it
3
The diagram shows two straight lines crossing at a point.Diagram NOT accurately drawn

(a) Write down the size of the angle marked $x$ . Give a reason for your answer.

(b) Work out the size of the angle marked $y$ . Give a reason for your answer.
Level 2 · 4 marksTry it
4
The diagram shows three angles on a straight line.Diagram NOT accurately drawn

Work out the size of the angle marked $x$ . Give a reason for your answer.
Level 2 · 2 marksTry it
5
$ABC$ is a triangle with $AB = AC$ . $BCD$ is a straight line.

Angle $BAC = 44°$ .Diagram NOT accurately drawn

Work out the size of the angle marked $x$ . You must give reasons for each stage of your working.
Level 3 · 5 marksTry it

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