1. Whiteboardmaths.com
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2. Area of a Triangle
The area of a triangle = ½ the area of the surrounding rectangle/parallelogram
base
height
Area of a triangle = ½ base x height

3. Area of a Triangle
The area of a triangle = ½ the area of the surrounding rectangle/parallelogram
base
height
rectangle area =
triangle area = ½ rectangle area
Area of a triangle = ½ base x height

4. Find the area of the following triangles.
8 cm
10 cm
14 cm
12 cm
9 cm
16 cm
Area = ½ b x h
3.2 m
4.5 m
7 mm
5 mm
Area = ½ x 8 x 9
= 36 cm2
Area = ½ x 10 x 12
= 60 cm2
Area = ½ x 14 x 16
= 112 cm2
Area = ½ x 3.2 x 4.5
= 7.2 m2
Area = ½ x 7 x 5
= mm2