1. Pythagoras – Isosceles Triangles – Bingo Method
Students should choose nine answers from the grid and place them
randomly into a 3x3 square in their book.
You may want to pause your display and choose questions
according to difficulty during the game.
Depending on time, students could win with
a line, an X, or a ‘full house’ (all).

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. Pythagoras with Isosceles Triangles
BINGO! 45 54 23 82 37 12 76 25 91
Pythagoras with Isosceles Triangles

4. Choose your numbers…
7.2
8.5 15
4.5
20.5
12.5
7.8 48
11.9
5.4
79.6
18.7
15.9
9.6
31.7
7.5
Draw a 3x3 grid in your book.

5. Find 𝑥
(1 dp) 𝑥
10 cm
13 cm 𝑥=
= 11.9 cm

6. Find 𝑥
(1 dp)
9 m 𝑥
10 m
𝑥= 92−52
= 7.5 m

7. Find 𝑥
(1 dp)
12 m
11 m 𝑥
𝑥= 122−112 × 2
= 9.6 m

8. Find 𝑥
(1 dp) 𝑥
16 cm
22 cm
𝑥= 222−82
= 20.5 cm

9. What is the area of this triangle?
(1 dp)
10 mm ℎ
16 mm
ℎ𝑒𝑖𝑔ℎ𝑡= 102−82
𝑎𝑟𝑒𝑎= 1 2 𝑏ℎ
= 48 mm2

10. Find 𝑥
(1 dp)
8 cm 𝑥
6 cm 𝑥=
= 8.5 cm

11. The area of this triangle is 30 cm2. Find 𝑥
(1 dp) 𝑥
6 cm
10 cm
𝑏𝑎𝑠𝑒= 30×2 6 𝑥=
= 7.8 cm

12. Find 𝑥
(1 dp)
25 m
20 m 𝑥
𝑥= 252−202
= 15 m

13. Find 𝑥
(1 dp) 𝑥
3 cm
9 cm 𝑥=
= 5.4 cm

14. What is the area of this triangle?
(1 dp)
8 cm ℎ
12 cm
ℎ𝑒𝑖𝑔ℎ𝑡= 82−62
𝑎𝑟𝑒𝑎= 1 2 𝑏ℎ
= 31.7 cm2

15. Find 𝑥
(1 dp) 𝑥
14 mm
20 mm
𝑥= 202−72
= 18.7 mm

16. What is the area of this triangle?
(1 dp) ℎ
5 m
7 m
ℎ𝑒𝑖𝑔ℎ𝑡= 52−3.52
𝑎𝑟𝑒𝑎= 1 2 𝑏ℎ
= 12.5 m2

17. The area of this triangle is 24 cm2. Find 𝑥
(1 dp) 𝑥
6 cm
8 cm
ℎ𝑒𝑖𝑔ℎ𝑡= 24×2 8 𝑥=
= 7.2 cm2

18. What is the area of this triangle?
(1 dp)
4 km ℎ
3 km
ℎ𝑒𝑖𝑔ℎ𝑡= 32−22
𝑎𝑟𝑒𝑎= 1 2 𝑏ℎ
= 4.5 km2

19. Find 𝑥
(1 dp)
15 cm
14 cm 𝑥 𝑥=
= 15.9 cm

20. What is the area of this triangle?
(1 dp)
23 cm
7 cm ℎ
ℎ𝑒𝑖𝑔ℎ𝑡= 232−3.52
𝑎𝑟𝑒𝑎= 1 2 𝑏ℎ
= 79.6 cm2

22. tom@goteachmaths.co.uk Questions? Comments? Suggestions?
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