मराठी

Prove that the points A (1, -3), B (-3, 0) and C (4, 1) are the vertices of an isosceles right-angled triangle. Find the area of the triangle. - Mathematics

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प्रश्न

Prove that the points A (1, -3), B (-3, 0) and C (4, 1) are the vertices of an isosceles right-angled triangle. Find the area of the triangle.

बेरीज
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उत्तर

AB =`sqrt((-3 -1)^2 + (0 +3)^2) = sqrt(16+9) = sqrt(25)` = 5

BC =`sqrt((4 + 3)^2 + (1 +0)^2)= sqrt(49+1)= sqrt(50) = 5sqrt(2)`

CA =`sqrt((1 -4)^2 + (-3 - 1)^2) = sqrt(9 + 16) = sqrt(25)` = 5

∵ AB = CA

A, B, C are the vertices of an isosceless triangle.

AB2 + CA2  = 25 + 25 = 50

BC2 = `(5sqrt(2))^2` = 50

∴ AB2 + CA2 = BC2

Hence, A, B, C are the vertices of a right-angled triangle.

Hence, ΔABC is an isosceles right-angled triangle.

Area of ΔABC = `(1)/(2) xx "AB" xx "CA"`

= `(1)/(2) xx 5 xx 5`

= 12.5 sq.units

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पाठ 28: Distance Formula - Exercise 28 [पृष्ठ ३३५]

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सेलिना Concise Mathematics [English] Class 9 ICSE
पाठ 28 Distance Formula
Exercise 28 | Q 13 | पृष्ठ ३३५

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