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The difference between the sides at right angle in a right-angled triangle is 7 cm. The area of the triangle is 60 cm2. Find its perimeter. |
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Answer» Let x cm be the one of the sides, then (x – 7) cm be another side. Area of triangle = 60 cm2 (given) We know, Area of triangle = 1/2(Base x height) 60 = 1/2(x (x – 7)) 120 = x2 – 7x or x2 – 7x – 120 = 0 Solving above equation, we have (x – 15)(x + 8) = 0 x = 15 or x = -8 Since length measure cannot be negative, so neglect x = -8 One side = 15 cm Another Side = x – 7 = 15 – 7 = 8 cm Apply Pythagoras theorem: Hypotenuse2 = Base2 + Perpendicular2 Hypotenuse2 = √(152 + 82) Hypotenuse = √289 = 17 Therefore, perimeter of triangle = Sum of all the sides = (15 + 8 + 17) cm = 40 cm |
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