Remember: A triangle has 3 straight sides and is closed all round. Colour, size and tilt do not matter.
Spot the triangle
Count the straight sides.
1
Which shape is a triangle?
ABC
2
Which shape is NOT a triangle?
ABC
3
How many straight sides does a triangle have?
4
How many sides does this shape have?
5
This shape is a triangle.
TrueFalse
6
A big triangle and a small triangle are both triangles.
TrueFalse
7
Circle every triangle.
ABCD
8
Join each shape to its number of sides.
1triangle
2square
3hexagon
A3 sides
B6 sides
C4 sides
9
Pip cuts off one corner of a triangle. It now has 4 sides. Is it still a triangle?
YesNo
10
Pip turns a triangle upside down. Is it still a triangle?
YesNo
11
Draw a triangle.
12
Tell how you know a shape is a triangle.
Scan the code at the top to mark this sheet on screenTake a photo of your answers or type them. It is marked for you automatically, and your score is kept.
Answer key · Set A
What makes a triangle
1C A triangle has 3 straight sides. Shape C has 3.
2B Shape B has 4 sides. A triangle has only 3, big or small.
33 A triangle has 3 sides and 3 corners.
44 Count the straight sides: 4. It is not a triangle.
5False It has 4 sides. A triangle has 3.
6True Size does not matter. Both have 3 straight sides.
7A, C A and C each have 3 straight sides. B has 4 and D has 6.
81-A, 2-C, 3-B
9No A triangle has exactly 3 sides. With 4 sides it is a new shape.
10Yes Turning does not change the 3 straight sides. It is still a triangle.
12Your own words: a grown-up reads it.
Mark each answer, count the right ones and write the score on the sheet.