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
Deepak BoraNewbie
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.