Robinson Tuition
Grade 4 · Foundation and Higher · free GCSE maths worksheet

Angles in parallel lines

Alternate, corresponding and co-interior angles.

17 original questions, 63 marks. Print the worksheet, mark it with the answers sheet, and use the solutions to see every step written out by hand.

Worksheet PDFWorked solutions PDFAnswers PDF

The questions

1

AB and CD are parallel straight lines.

A straight line crosses AB at E and crosses CD at F. On line AB, A is to the left of E and B is to the right of E. On line CD, C is to the left of F and D is to the right of F.

Angle AEF = 62°.

Work out the size of angle CFE.

Give a reason for each stage of your working.

62°ABCDEFDiagram NOT accurately drawn
4 marks
Show answer
118°
2

Two straight lines are parallel. A third line crosses them. Two angles lie between the parallel lines, on opposite sides of the crossing line, in a Z shape. One of these angles is 72°.

Write down the size of the other angle and the name of this type of angle.

2 marks
Show answer
72 degrees, alternate angles
3

Two straight lines are parallel. A third line crosses them. Two angles are in matching positions, one at each crossing, in an F shape. One of these angles is 115°.

Write down the size of the other angle and the name of this type of angle.

2 marks
Show answer
115 degrees, corresponding angles
4

PQ and RS are parallel straight lines.

A straight line crosses PQ at E and crosses RS at F. On line PQ, P is to the left of E and Q is to the right of E. On line RS, R is to the left of F and S is to the right of F.

Angle QEF = 74°.

  1. Work out the size of angle RFE. Give a reason for your answer.
  2. Work out the size of angle EFS. Give a reason for your answer.
74°PQRSEFDiagram NOT accurately drawn
4 marks
Show answer
a) 74° b) 106°
5

Two straight lines are parallel. A third line crosses them. Two angles lie between the parallel lines, on the same side of the crossing line, in a C shape. One of these angles is 108°.

Work out the size of the other angle. Give the name of this type of angle.

2 marks
Show answer
72 degrees, co-interior angles
6

Two straight lines are parallel and are crossed by a third line. Write down the name of each pair of angles, and say what you know about their sizes.

  1. Two angles in a Z shape, between the parallel lines.
  2. Two angles in an F shape, in matching positions.
  3. Two angles in a C shape, between the parallel lines.
3 marks
Show answer
a) alternate angles, equal b) corresponding angles, equal c) co-interior angles, add up to 180 degrees
7

AB and CD are parallel straight lines.

A straight line GEFH crosses AB at E and crosses CD at F, where G is above the line AB and H is below the line CD. On line AB, A is to the left of E and B is to the right of E. On line CD, C is to the left of F and D is to the right of F.

Angle GEB = 63°.

  1. Work out the size of angle EFD. Give a reason for your answer.
  2. Work out the size of angle CFH. Give a reason for your answer.
63°ABCDEFGHDiagram NOT accurately drawn
4 marks
Show answer
a) 63° b) 63°
8

Two straight lines are parallel and are crossed by a third line. Two alternate angles are (3x + 10)° and (5x − 30)°.

Work out the value of x.

3 marks
Show answer
20
9

Two straight lines are parallel and are crossed by a third line. Two corresponding angles are (4x − 12)° and (x + 30)°.

Work out the value of x, and the size of each angle.

3 marks
Show answer
x = 14, angles 44 degrees
10

DE and FG are parallel straight lines.

Triangle ABC is drawn so that A lies on DE, and B and C both lie on FG.

D is to the left of A and E is to the right of A.

Angle DAB = 48° and angle ACB = 63°.

Work out the size of angle BAC.

Give a reason for each stage of your working.

48°63°ABCDEFGDiagram NOT accurately drawn
4 marks
Show answer
69°
11

Two straight lines are parallel and are crossed by a third line. Two co-interior angles are (2x + 15)° and (3x − 5)°.

Work out the value of x, and the size of the larger angle.

3 marks
Show answer
x = 34, larger angle 97 degrees
12

A straight line crosses line AB at the point P and crosses line CD at the point Q, where P is above Q. On line AB, B is to the right of P. On line CD, D is to the right of Q.

Angle QPB, between PQ and PB and inside the region between the two lines, is 104°.

Angle PQD, between QP and QD and inside the region between the two lines, is 76°.

Show that AB is parallel to CD.

Give reasons for your answer.

104°76°ABCDPQDiagram NOT accurately drawn
4 marks
Show answer
104° + 76° = 180°; angle QPB and angle PQD are co-interior angles; co-interior angles adding to 180° means the lines are parallel
13

AB and CD are parallel straight lines.

E lies on AB. F and G both lie on CD, with F to the left of G.

A is to the left of E and B is to the right of E.

EF = EG and angle AEF = 64°.

Work out the size of angle FEG.

Give a reason for each stage of your working.

64°EFGABCDDiagram NOT accurately drawn
5 marks
Show answer
52°
14

ABCD is a trapezium in which AB is parallel to DC.

The diagonal BD is drawn.

Angle DAB = 74° and angle ADB = 68°.

  1. Work out the size of angle ABD. Give a reason for your answer.
  2. Work out the size of angle BDC. Give a reason for your answer.
74°68°ABCDDiagram NOT accurately drawn
5 marks
Show answer
a) 38° b) 38°
15

AB and CD are parallel straight lines.

E lies on AB. F and G both lie on CD, with F to the left of G.

A is to the left of E and B is to the right of E.

Angle AEF = 67° and angle BEG = 67°.

Show that triangle EFG is an isosceles triangle.

Give a reason for each stage of your working.

67°67°EFGABCDDiagram NOT accurately drawn
5 marks
Show answer
Angle EFG = 67° (alternate with AEF) and angle EGF = 67° (alternate with BEG); two equal base angles mean triangle EFG is isosceles
16

AB and CD are parallel straight lines. A straight line crosses them both.

Two co-interior angles between the parallel lines are (3x + 20)° and (2x − 15)°.

Work out the size of the smaller of these two angles.

You must show all your working.

5 marks
Show answer
55°
17

AB and CD are parallel straight lines, with AB above CD.

E lies on AB and G lies on CD. F is a point between the two lines, to the right of both E and G, so that EFG forms a zigzag.

Angle BEF = 38° and angle DGF = 44°, where B is to the right of E and D is to the right of G.

Work out the size of angle EFG.

Give a reason for each stage of your working.

38°44°xABCDEFGDiagram NOT accurately drawn
5 marks
Show answer
82°

Every question here is original and written by Robinson Tuition. The grade follows the Edexcel grade descriptors and suits AQA and OCR too; this is not an exam-board paper.

All Grade 4 topics