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Question
A wire ; 112 cm long is bent to form a right angled triangle. If the hypotenuse is 50 cm long, find the area of the triangle.
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Solution
Perimeter of a right angled triangle = 112 cm
Hypotenuse = 50 cm
∴ Sum of other two sides = 112 – 50 = 62 cm
Let the length of first side = x
and length of other side = 62 – x
According to the condition
(x)2 + (62 – x)2 = (50)2 ...(By Pythagorus Theorem)
⇒ x2 + 3844 – 124x + x2 = 2500
⇒ 2x2 – 124x + 3844 – 2500 = 0
⇒ 2x2 – 124 + 1344 = 0
⇒ x2 – 62x + 672 = 0 ...(Dividing by 2)
⇒ x2 – 48x – 14x + 672 = 0
⇒ x(x – 48) –14(x - 48) = 0
⇒ (x – 48)(x – 14) = 0
Either x – 48 = 0,
then x = 48
or
x – 14 = 0,
then x = 14
(i) If x = 48,
then one side = 48cm
and other side = 62 – 48 = 14cm
(ii) If x = 14,
then one side = 14cm
and other side = 62 – 14 = 48
Hence sides are 14cm, 48cm.
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