Maths 3rd grade - Unit 3:

PLANE FIGURESby Maria Adrover

CEIP CALONGE

POLYGONS: Definition and parts

A polygon is a closed polygonal line (straight) and its inside.

THE MOST COMMON POLYGONS

Remember! The polygons are classified by the number of sides

THE TRIANGLES

A triangle is a polygon with 3 sides, 3 vertexes and 3 angles.

Classifying triangles by sides

Classifying triangles by angles

THE QUADRILATERALS

A quadrilateral is a polygon with 4 sides, 4 vertexes and 4 angles.

Classifying quadrilaterals

Types of parallelograms

THE PERIMETER

The perimeter of a polygon is the addition (+) of all the sides lenghts.

THE SQUARE CENTIMETRE (cm2)

The area is the number of square centimetres needed to cover a figure.

AREA OF THE RECTANGLE

AREA OF THE SQUARE

CIRCLE AND CIRCUMFERENCE

PARTS OF A CIRCLE

HOW TO USE A COMPASS

Mark the center of the circumference.

Stick the compass needle into the centre.

Turn the compass.