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If the Sides of the Triangle Are in the Ratio 1: Sqrt2: 1, Show that is a Right-angled Triangle.

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Question

If the sides of the triangle are in the ratio 1: `sqrt2`: 1, show that is a right-angled triangle.

Sum
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Solution

Let, the sides of the triangle be, x: `sqrt2`x and x.

AB2 + BC2 = x2 +x2 = 2x2

AC2 = `(sqrt2 x)^2` = 2x2

AB2 + BC2 = AC2 

Conversely, if in any triangle, the square on the largest side of the triangle is equal to the sum of the squares on remaining two sides, then the triangle is a right-angled triangle and the angle opposite to the largest side is a right-angle.

Therefore, Δ ABC is a right-angled triangle.

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Chapter 13: Pythagoras Theorem [Proof and Simple Applications with Converse] - Exercise 13 (A) [Page 159]

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Selina Concise Mathematics [English] Class 9 ICSE
Chapter 13 Pythagoras Theorem [Proof and Simple Applications with Converse]
Exercise 13 (A) | Q 8 | Page 159

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