CBSE 10th Class Mathematics

Past year question paper

Year 2020

SET 1, Code Number – 30/5/1

Question Number – 29 [b]

graphical problem

vertices of an isosceles right triangle

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# Show that the points (7, 10), (-2, 5) and (3, -4) are vertices of an isosceles right triangle

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Let A (7, 10) B(-2, 5) C(3, -4) be the vertices of triangle.

Distance between two points =√ [ (x2-x1)² – (y2-y1)² ]

AB = √[9² + 5²] = √106

BC = √[5² + 9²] = √106

CA =√[4² + 14²] = √ 212

(by Pythagoras theorem)

AB² + BC² = AC²

√106² + √106² =√212²

106 + 106 = 212

∴ ABC is an isosceles right angled Δ.