An angle is a measure of turn. It shows how far something has rotated.

A right angle is a square corner or a quarter turn.

An angle that is smaller than a right angle is an acute angle.

An angle that is greater than a right angle but smaller than a straight line is an obtuse angle.

An angle that is greater than a straight line up to a full turn is a reflex angle.

Use the terms acute, obtuse and reflex when comparing angles to a right angle

Maths

In this unit pupils will compare the size of angles where there is a clear visual difference and use the terms acute, obtuse and reflex when describing the size of angles or amount of rotation with relation to right angles using a unit called degrees. In the future unit pupils will use knowledge of shape properties to draw, sketch and identify shapes.

In the prior unit pupils completed and composed symmetrical shapes from two congruent shapes and investigate lines of symmetry in 2D shapes. In this unit pupils will compare the size of angles where there is a clear visual difference and use the terms acute, obtuse and reflex when describing the size of angles or amount of rotation with relation to right angles using a unit called degrees.

Angles: compare, name, estimate and measure angles

Look at the hands on this clock face and the arrow. The angle formed is __________.

This is a trapezium. Look carefully at the vertices and the angles inside the shape. Complete the sentence. There are {{ }} acute angles in the trapezium.

The trapezium has two right angles and two acute angles. 

The trapezium has two right angles and two obtuse angles. 

The trapezium has two right angles, one acute angle and one obtuse angle.

This is a trapezium. Look carefully at the vertices and the angles inside the shape. Which statement is correct?

Look at the image. This shape has {{ }} right angles.

This shape has one pair of parallel sides. True or false?

Complete the sentence. A parallelogram has {{ }} vertices.

A polygon with four equal sides and four right angles.

A polygon with three sides and three vertices.

A polygon with five sides and five vertices.

The minute hand shows 4 o’clock. The minute hand moves a quarter turn clockwise. What time is shown?

Which of the angles shown is the smallest?

This lesson will soon be taken down.

Use the terms acute, obtuse and reflex when comparing angles to a right angle

Lesson outcome