1. Similar Triangles – Foundation – GCSE Questions
These questions are the same format as previous GCSE exams.
COPY means they use the exact same numbers as the original GCSE question.
Otherwise, they are clone questions using different numbers.
The worksheets are provided in a variety of sizes.

2. Printing To print handouts from slides -
Select the slide from the left. Then click:
File > Print > ‘Print Current Slide’
To print multiple slides -
Click on a section title to highlight all those slides,
or press ‘Ctrl’ at the same time as selecting slides to
highlight more than one. Then click:
File > Print > ‘Print Selection’
To print double-sided handouts -
Highlight both slides before using ‘Print Selection’.
Choose ‘Print on Both Sides’ and ‘Flip on Short Edge’.

3. GCSE GCSE Edexcel Foundation: June 2017 Paper 2, Q21B B C
ABC and DEA are straight lines.
DC is parallel to EB.
AC = 7.8 cm
AB = 5.2 cm
EB = 3.2 cm
(a) Work out the length of DC.
ABC and DEA are straight lines.
DC is parallel to EB.
AC = 7.8 cm
AB = 5.2 cm
EB = 3.2 cm
(a) Work out the length of DC. cm cm
(2)
(2)
AD = 6.36 cm
(b) Work out the length of ED.
AD = 6.36 cm
(b) Work out the length of ED. cm cm
(2)
(2)
(Total for Question 1 is 4 marks)
(Total for Question 1 is 4 marks)

5. GCSE GCSE GCSE GCSE Edexcel Foundation: June 2017 Paper 3, Q21
3 cm
14 cm 1
3 cm
14 cm
10.5 cm
10.5 cm
4 cm
4 cm
17.5 cm
17.5 cm
5 cm
5 cm
Show that these two triangles are mathematically similar.
Show that these two triangles are mathematically similar.
(Total for Question 1 is 2 marks)
(Total for Question 1 is 2 marks)
GCSE
GCSE
Edexcel Foundation: June 2017 Paper 3, Q21
Edexcel Foundation: June 2017 Paper 3, Q21 1
3 cm
14 cm 1
3 cm
14 cm
10.5 cm
10.5 cm
4 cm
4 cm
17.5 cm
17.5 cm
5 cm
5 cm
Show that these two triangles are mathematically similar.
Show that these two triangles are mathematically similar.
(Total for Question 1 is 2 marks)
(Total for Question 1 is 2 marks)

7. GCSE GCSE Edexcel Foundation: June 2018 Paper 3, Q27
Triangle ABC and DEF are similar. E 1
Triangle ABC and DEF are similar. E B B
6.5 cm
6.5 cm
2.6 cm
2.6 cm
1.4 cm
1.4 cm D D A C F A C F
7.5 cm
7.5 cm
(a) Work out the length of EF.
(a) Work out the length of EF. cm cm
(2)
(2)
(b) Work out the length of AC.
(b) Work out the length of AC. cm cm
(2)
(2)
(Total for Question 1 is 4 marks)
(Total for Question 1 is 4 marks)

9. GCSE Edexcel Foundation: June 2017 Paper 2, Q21B C
ABC and DEA are straight lines.
DC is parallel to EB.
AC = 7.8 cm
AB = 5.2 cm
EB = 3.2 cm
(a) Work out the length of DC. cm
(2)
AD = 6.36 cm
(b) Work out the length of ED. cm
(2)
(Total for Question 1 is 4 marks)

11. GCSE Edexcel Foundation: June 2018 Paper 3, Q27 1
Triangle ABC and DEF are similar. E B
6.5 cm
2.6 cm
1.4 cm D A C F
7.5 cm
(a) Work out the length of EF. cm
(2)
(b) Work out the length of AC. cm
(2)
(Total for Question 1 is 4 marks)

12. Calculate scale factor:
GCSE
Edexcel Foundation: June 2017 Paper 2, Q21 D 1 E x
3.2
5.2 A B C
7.8
ABC and DEA are straight lines.
DC is parallel to EB.
AC = 7.8 cm
AB = 5.2 cm
EB = 3.2 cm
(a) Work out the length of DC.
Calculate scale factor:
7.8 ÷ 5.2 = 1.5
3.2 x 1.5 = x = 4.8
4.8 cm
(2)
AD = 6.36 cm
(b) Work out the length of ED.
6.36 y
4.16
6.36 ÷ 1.5 = 4.24
2.12
y = = 2.12 cm
(2)
(Total for Question 1 is 4 marks)

13. GCSE
Edexcel Foundation: June 2017 Paper 3, Q21 A B 1
3 cm
14 cm
10.5 cm
4 cm
17.5 cm B
5 cm A C C
Show that these two triangles are mathematically similar.
C: =3.5
A: =3.5
All sides have been enlarged by the same scale factor (3.5: the triangles are mathematically similar.
B: =3.5
(Total for Question 1 is 2 marks)

14. 2.6 × scale factor = 6.5 scale factor = 6.5 ÷ 2.6 = 2.5
GCSE
Edexcel Foundation: June 2018 Paper 3, Q27 1
Triangle ABC and DEF are similar. E B
6.5 cm
2.6 cm
1.4 cm D A C F
7.5 cm
(a) Work out the length of EF.
2.6 × scale factor = 6.5
scale factor = 6.5 ÷ 2.6 = 2.5
BC × scale factor = EF
1.4 × 2.5 = 3.5
3.5 cm
(2)
(b) Work out the length of AC.
AC × scale factor = DF
AC × 2.5 = 7.5
AC = 7.5 ÷ 2.5 = 3 3 cm
(2)
(Total for Question 1 is 4 marks)

15. tom@goteachmaths.co.uk Questions? Comments? Suggestions?
…or have you found a mistake!?
Any feedback would be appreciated .
Please feel free to