Define a right angle:

A right angle is an angle of 90°.

Define a straight angle:

A straight angle is an angle of 180°. It forms a straight line and is the double of a right angle.

Define an acute angle:

An acute angle is an angle of under 180°.

Define an obtuse angle.

An obtuse angle is an angle of above 180°.

123°

Obtuse angle

What does an angle of 360° make?

A full circle. It is the double of a straight angle and the quadruple of a right angle.

57°

Acute angle

360°

Full circle

90°

Right angle

180°

Straight angle

Define a square:

A square is a geometrical figure with four sides of equal length and four angles of equal measure.

Define a side in a geometrical figure:

A side is (basically) one of the lines in the figure.

How many right angles does a square have?

4

Define a rectangle:

A rectangle is a geometrical figure with two pairs of sides and angles of equal length and measure.

How many right angles are there in a rectangle?

4

Define a circle:

A circle is the collection of points that are at the same distance from another single point, called the origin(O).

How many angles of 360° are there in a circle?

1