Question

20. Find the roots of the equation x - 2x - 8 = using quadratic formula
21. Find the area of the triangle whose vertices are AB.) 17.) .
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Answer 1

Answer:

concept : if three points A

$(x1,y1)$

, B

$(X2,Y2)$

and C

$(X3,Y3)$

form a triangle ABC.

then, area of triangle ABC =

$\frac{1}{2} (x1(y2-y1) + x2(y3 - y1) + x3(y1 - y2))$

here given, three points (a, b + c), (b, c + a) and (c, a + b)

then, area of triangle formed by these points = 1/2 [ a(c + a - a - b) + b(a + b - b - c) + c(b + c - c - a)]

= 1/2 [a(c - b) + b(a - c) + c(b - a)]

= 1/2 [ ac - ab + ba - bc + cb - ac ]

= 0

hence, area of triangle whose vertices are (a, b + c), (b, c + a) and (c, a + b) = 0

[important point : if area of triangle becomes zero, it means vertices of triangle is collinear. I mean, they lie in same line . ]

hope it helps you ♥️♥️

@ARSH☺️☺️