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The diagram shows a right-angled triangle.

All the measurements are in centimetres.

The area of the triangle is 18cm^2

Work out the length of the shortest side of the triangle.You must show all your working

The diagram shows a rightangled triangle All the measurements are in centimetres The area of the triangle is 18cm2 Work out the length of the shortest side of t class=

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thebecks

Answer:

short side = 4

Step-by-step explanation:

area = 1/2BH

18 = 1/2(x - 1)(x + 4)

18 = 1/2(x² + 4x - x - 4)

multiply both sides of the equation by 2:

36 = x² + 3x - 4

x² + 3x - 40 = 0

(x + 8)(x - 5) = 0

x = 5

short side = 5 - 1 = 4

The shortest length of the right angled triangle is 4 cm.

Area of a triangle:

  • area = 1 / 2 bh

where

b = base

h = height

Therefore,

area = 18 cm²

18 = [tex]\frac{1}{2}[/tex] × (x - 1)(x + 4)

36 = (x - 1)(x + 4)

x² + 4x - x - 4 = 36

x² + 3x - 4 = 36

x² + 3x - 4 - 36 = 0

x² + 3x - 40 = 0

x² - 5x + 8x - 40 = 0

x(x - 5) + 8(x - 5) = 0

(x + 8)(x - 5) = 0

x = -8 or 5

we can only use positive numbers.

Therefore,

x = 5

The shortest sides is definitely one of the 2 legs . The hypotenuse of a triangle is the longest side.

Therefore,

h = x - 1 = 5 - 1 = 4 cm

b = x + 4 = 5 + 4 = 9 cm

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