Difference between revisions of "Area"

Revision as of 11:08, 26 March 2019

Area is the size of a surface.

If a rectilinear shape is drawn on a grid the area can be found by counting the number of squares inside the shape.


The shape has 20 squares inside it, so the area is 20 squares.	This shape has an area of 14 squares.	This shape has an area of 15 squares.

Area is the size of a surface.

If a rectilinear shape is drawn on a grid the area can be found by counting the number of squares inside the shape.


The shape has 20 squares inside it, so the area is 20 squares.	This shape has an area of 14 squares.	This shape has an area of 15 squares.

If an unusual shape is drawn on a grid the area can be estimated. The answer will not be exactly correct, but it will be close.


This shape has 12 full squares and 3 half squares. So the area is 12 + 3.5 = 15.5 squares.	This shape has 10 full squares, 2/3 of a square, 4 half squares and 1/3 of a square. So the area is 10 + 2/3 + 4 + 1/3 = 15 squares.	This circle has 12 full squares, 4 nearly full squares, 4 nearly empty squares, 6 half squares. The area is difficult to estimate but it is around 19 squares.

The units of area are not usually 'squares', they are either metres squared (m²) or centimetres squared (cm²).

The area of a rectangle or a square can also be found if the length of the sides is known.

To find the area of a rectangle or square; multiply the base by the height.


\(area = base \times height\) \(area = 5 \times 5\) \(area = 25m^2\)	\(area = base \times height\) \(area = 7 \times 4\) \(area = 28cm^2\)	\(area = base \times height\) \(area = 6\times 4.5\) \(area = 27cm^2\)

The area of a triangle can be found by multiplying half the base by the height.


\(area = base \times height\) \(area = 6 \times 3\) \(area = 18cm^2\)	\(area = base \times height\) \(area = 4 \times 6\) \(area = 24cm^2\)	\(area = \frac{1}{2} \times base \times height\) \(area = \frac{1}{2} \times 5 \times 7\) \(area = 17.5cm^2\)

@@ Line 74: / Line 74: @@
 <math>area = 27cm^2</math>
+|}
+: The [[area]] of [[parallelogram]]s can be found by [[multiplying]] the [[base]] by the [[height]].
+: The [[area]] of a [[triangle]] can be found by [[multiplying]] half the [[base]] by the [[height]].
+{| class="wikitable"
+|-
+|[[File:ParallelogramArea1.png|center|200px]]
+|[[File:ParallelogramArea2.png|center|200px]]
+|[[File:TriangleArea1.png|center|200px]]
+|-
+| style="height:20px; width:200px; text-align:center;" |
+<math>area = base \times height</math>
+<math>area = 6 \times 3</math>
+<math>area = 18cm^2</math>
+| style="height:20px; width:200px; text-align:center;" |
+<math>area = base \times height</math>
+<math>area = 4 \times 6</math>
+<math>area = 24cm^2</math>
+| style="height:20px; width:200px; text-align:center;" |
+<math>area = \frac{1}{2} \times base \times height</math>
+<math>area = \frac{1}{2} \times 5 \times 7</math>
+<math>area = 17.5cm^2</math>
 |}