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Shape and Space. Triangles. Area of a right-angled triangle. 1. 2. What proportion of this rectangle has been shaded?. 4 cm. 8 cm. What is the shape of the shaded part?. What is the area of this right-angled triangle?. Area of the triangle = × 8 × 4 =. 4 × 4. = 16 cm 2.
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Shape and Space Triangles
Area of a right-angled triangle 1 2 What proportion of this rectangle has been shaded? 4 cm 8 cm What is the shape of the shaded part? What is the area of this right-angled triangle? Area of the triangle = × 8 × 4 = 4 × 4 = 16 cm2
Area of a right-angled triangle Area of a triangle = × base × height 1 1 = bh 2 2 We can use a formula to find the area of a right-angled triangle: height, h base, b
Area of a right-angled triangle Area = × base × height 1 1 2 2 = × 8 × 6 Calculate the area of this right-angled triangle. To work out the area of this triangle we only need the length of the base and the height. 8 cm 6 cm 10 cm We can ignore the third length opposite the right angle. = 24 cm2
Area of a triangle 1 2 What proportion of this rectangle has been shaded? 4 cm 8 cm Drawing a line here might help. What is the area of this triangle? Area of the triangle = × 8 × 4 = 4 × 4 = 16 cm2
Area of a triangle Area of a triangle = × base × perpendicular height perpendicular height 1 1 base 2 2 Area of a triangle = bh The area of any triangle can be found using the formula: Or using letter symbols,
The area of a triangle b b h h h b Any side of the triangle can be taken as the base, as long as the height is perpendicular to it:
Area of a triangle Area of a triangle = bh = × 7 × 6 1 1 2 2 What is the area of this triangle? 6 cm 7 cm = 21 cm2