Step-by-step Maths Level 1: Sides and corners
Part of the Step-by-step Maths Level 1 shapes chapter. Chapter overview · whole chapter on one page
Sides and corners
A side is a straight edge. A corner is where two sides meet.
A square and a rectangle each have 4 sides and 4 corners. A triangle has 3 sides and 3 corners. A circle has no sides and no corners.
Key ideas
- A side is a straight edge.
- A corner is where two sides meet.
- A circle has no straight sides and no corners.
Method. Trace the outline with your finger.
- Trace each edge. Count each straight edge once.1, 2, 3
- Count the sides. The triangle has three straight sides.3
- Write the answer. 3
Check. The triangle has 3 corners too.
Watch out. Count each edge once. Do not count a side twice.
Method. Count where two sides meet.
- Find each corner. A corner is where two sides meet.top left, top right, bottom left, bottom right
- Count the corners. There are four corners.4
- Write the answer. 4
Check. A rectangle has 4 sides and 4 corners.
Watch out. Count each corner once.
Method. A circle is round, so look for corners.
- Look for corners. There is no point where two straight sides meet.no corners
- Count the corners. A circle has none.0
- Write the answer. 0
Check. Zero corners means none.
Watch out. The round shape has no corners, so write 0.
Watch out
Watch out. Count sides and corners separately. Each corner joins two sides.
Exam tip
Grown-up tip. Trace each shape with a finger and count the edges out loud. Ask: “How many corners?” before you count the sides.
Exercise 10B Sides and corners
Non-calculatorMethod. Count the straight edges. A curved edge is not a side.
- Trace the outline with your finger. Count each straight edge once.rectangle
- Count the straight sides. A rectangle has 2 long sides and 2 short sides.4
- Write the answer. 4
Check. The number of corners is the same as the number of straight sides for these shapes. ✓
Watch out. A curved line is not a side. Count only straight edges.
Method. Count the corners. A corner is where two straight sides meet.
- Find each corner. Mark each point where two straight sides meet.square
- Count the corners. A square has 4 corners.4
- Write the answer. 4
Check. Count the corners again, one at a time. ✓
Watch out. Count each corner once. The round shape has none.
Method. Count the straight edges. A curved edge is not a side.
- Trace the outline with your finger. Count each straight edge once.circle
- Count the straight sides. A circle has no straight sides.0
- Write the answer. 0
Check. A circle has no corners and no straight sides.
Watch out. A curved line is not a side. Count only straight edges.
Method. Count the corners. A corner is where two straight sides meet.
- Find each corner. Mark each point where two straight sides meet.square
- Count the corners. A square has 4 corners.4
- Write the answer. 4
Check. Count the corners again, one at a time. ✓
Watch out. Count each corner once. The round shape has none.
Method. Count the straight edges. A curved edge is not a side.
- Trace the outline with your finger. Count each straight edge once.square
- Count the straight sides. A square has 4 equal sides.4
- Write the answer. 4
Check. The number of corners is the same as the number of straight sides for these shapes. ✓
Watch out. A curved line is not a side. Count only straight edges.
Method. Count the corners. A corner is where two straight sides meet.
- Find each corner. Mark each point where two straight sides meet.square
- Count the corners. A square has 4 corners.4
- Write the answer. 4
Check. Count the corners again, one at a time. ✓
Watch out. Count each corner once. The round shape has none.
Method. Count the straight edges. A curved edge is not a side.
- Trace the outline with your finger. Count each straight edge once.triangle
- Count the straight sides. A triangle has 3 sides.3
- Write the answer. 3
Check. The number of corners is the same as the number of straight sides for these shapes. ✓
Watch out. A curved line is not a side. Count only straight edges.
Method. Count the corners. A corner is where two straight sides meet.
- Find each corner. Mark each point where two straight sides meet.triangle
- Count the corners. A triangle has 3 corners.3
- Write the answer. 3
Check. Count the corners again, one at a time. ✓
Watch out. Count each corner once. The round shape has none.
Method. Count the straight edges. A curved edge is not a side.
- Trace the outline with your finger. Count each straight edge once.rectangle
- Count the straight sides. A rectangle has 2 long sides and 2 short sides.4
- Write the answer. 4
Check. The number of corners is the same as the number of straight sides for these shapes. ✓
Watch out. A curved line is not a side. Count only straight edges.
Method. Count the corners. A corner is where two straight sides meet.
- Find each corner. Mark each point where two straight sides meet.circle
- Count the corners. A circle has no corners.0
- Write the answer. 0
Check. Count the corners again, one at a time. ✓
Watch out. Count each corner once. The round shape has none.
Method. Count the straight edges. A curved edge is not a side.
- Trace the outline with your finger. Count each straight edge once.circle
- Count the straight sides. A circle has no straight sides.0
- Write the answer. 0
Check. A circle has no corners and no straight sides.
Watch out. A curved line is not a side. Count only straight edges.
Method. Count the corners. A corner is where two straight sides meet.
- Find each corner. Mark each point where two straight sides meet.rectangle
- Count the corners. A rectangle has 4 corners.4
- Write the answer. 4
Check. Count the corners again, one at a time. ✓
Watch out. Count each corner once. The round shape has none.
Method. Count the straight edges. A curved edge is not a side.
- Trace the outline with your finger. Count each straight edge once.rectangle
- Count the straight sides. A rectangle has 2 long sides and 2 short sides.4
- Write the answer. 4
Check. The number of corners is the same as the number of straight sides for these shapes. ✓
Watch out. A curved line is not a side. Count only straight edges.
Method. Count the corners. A corner is where two straight sides meet.
- Find each corner. Mark each point where two straight sides meet.rectangle
- Count the corners. A rectangle has 4 corners.4
- Write the answer. 4
Check. Count the corners again, one at a time. ✓
Watch out. Count each corner once. The round shape has none.
Method. Count the straight edges. A curved edge is not a side.
- Trace the outline with your finger. Count each straight edge once.triangle
- Count the straight sides. A triangle has 3 sides.3
- Write the answer. 3
Check. The number of corners is the same as the number of straight sides for these shapes. ✓
Watch out. A curved line is not a side. Count only straight edges.
Method. Count the corners. A corner is where two straight sides meet.
- Find each corner. Mark each point where two straight sides meet.square
- Count the corners. A square has 4 corners.4
- Write the answer. 4
Check. Count the corners again, one at a time. ✓
Watch out. Count each corner once. The round shape has none.