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Maths · Grade 1 · Set C
What makes a triangle: a step further
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C
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Goal: 15 min
Score/ 11
Remember: A triangle has 3 straight sides and is closed all round. Colour, size and tilt do not matter.

Tilted and tricky

Count the straight sides. Tilting does not change them.

1
Pip says this tilted shape is a triangle. Is Pip right?
YesNo
2
Which shape is a triangle?
A
B
C
3
How many triangles are there?
4
A triangle and a square are side by side. How many sides do they have in all?
5
How many more sides does the hexagon have than the triangle?
6
Which shape has the fewest sides?
A
B
C
7
A triangle can have a square corner.
TrueFalse
8
Join each clue to a shape.
  1. 13 straight sides
  2. 24 straight sides
  3. 36 straight sides
  4. 4no straight sides
  • Acircle
  • Brectangle
  • Ctriangle
  • Dhexagon
9
Put the shapes in order. Fewest sides first.
  • triangle
  • hexagon
  • pentagon
  • rectangle
10
Pip draws 3 straight sides but leaves a gap. Is it a triangle?
YesNo
11
Circle every shape that is NOT a triangle.
A
B
C
12
Draw 2 triangles that do not look alike.
13
Tell how you know this shape is not a triangle.
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Answer key · Set C
What makes a triangle: a step further
1No Count the sides: it has 4 straight sides. A triangle has 3.
2C Shape C has 3 straight sides, even though it is turned around.
34 Count only the shapes with 3 straight sides: 4.
47 The triangle has 3 sides and the square has 4. 3 and 4 make 7.
53 A hexagon has 6 sides and a triangle has 3. 6 take away 3 is 3.
6A A triangle has 3 sides. A square has 4 and a pentagon has 5.
7True Only the 3 straight sides matter. A square corner is fine.
81-C, 2-B, 3-D, 4-A
91, 4, 3, 2 A triangle has 3 sides, a rectangle 4, a pentagon 5 and a hexagon 6.
10No A triangle is closed all round. A gap means it is not a triangle.
11A, C A has no straight sides and C has 8. Only B has 3.
13Your own words: a grown-up reads it.
Mark each answer, count the right ones and write the score on the sheet.