Constructing angles of 90° and 45°
I can construct angles of 90° and 45°.
Constructing angles of 90° and 45°
I can construct angles of 90° and 45°.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- When constructing the perpendicular, you are constructing a 90° angle
- Bisecting a 90° angle results in two angles, each measuring 45°
Keywords
Bisect - To bisect means to cut or divide an object into two equal parts.
Complementary angles - Complementary angles are a pair of angles that sum to 90°.
Supplementary angles - Supplementary angles are a pair of angles that sum to 180°.
Conjugate angles - Conjugate angles are a pair of angles that sum to 360°.
Common misconception
Pupils may use a protractor rather than a pair of compasses.
Remind pupils that a construction is done using a pair of compasses and ruler.
Equipment
Pair of compasses, protractor, ruler.
Licence
This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Lesson video
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Starter quiz
6 Questions
$$a$$° -
32°
$$b$$° -
64°
$$c$$° -
116°
Not a marked angle -
44°
Step 1 -
Set your compasses to a width equal to the shorter of the two legs.
Step 2 -
Place your compass needle on the vertex of the angle.
Step 3 -
Make an arc on each leg, then place the compass needle on one arc.
Step 4 -
Place the pencil on the vertex of the angle. Draw a circle.
Step 5 -
Repeat on the open endpoint of the other leg.
Step 6 -
Draw lines with a ruler to connect the points to form a rhombus.
Exit quiz
6 Questions
Angle BOC -
90°
Angle AOE -
45°
Angle AOD -
135°
Reflex angle AOE -
315°
Reflex angle AOD -
225°