IF D[-1/2 , 5/2 ] , E [ 7,3 ] , F [7/2 ,7/2 ] are the mid points of triangle ABC , then find the area of triangle ABC .ITS URGENT !!

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Okkkk
plzz try to do it tomorow xam is there of maths
Area of triangle is 1/2{(x1y2+x2y3+x3+y1)-(x2y1+x3y2+x1y3)} this formula??
sory i did n't got u ;(
bee fast yaar

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The Brainliest Answer!
2015-03-22T23:04:08+05:30

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     D (-1/2,  5/2),   E (7, 3)    and   F (7/2,  7/2)    are the midpoints of sides AB, BC and CA respectively. ABC is a triangle.

Area of triangle DEF :
=\frac{1}{2} | (x_D y_E + x_E y_F + x_F y_D) - ( y_D x_E + y_E x_F + y_F x_D ) |\\\\=\frac{1}{2} |\ \frac{-1}{2}*3+7*\frac{7}{2} +\frac{7}{2}*\frac{5}{2}-\ ( \frac{5}{2}*7+3*\frac{7}{2}+\frac{7}{2}*\frac{-1}{2} )\ |\\\\=\frac{57}{8}\\

The triangles ADE, BDF, DEF, EFC are all of equal size.  The reason is DE = 1/2 BC and Δ ADE is similar to Δ ABC.  Hence, area of Δ ADE = 1/4 * area of Δ ABC.

So area of Δ ABC = 57/2

2 5 2
2015-03-22T23:06:06+05:30
Area of triangle ABC = 1/2[ x1(y2 - y3) + x2 (y3 - y1) + x3 (y1 - y2) ] Area of triangle ABC = 4 area of triangle DEF Area of triangle DEF = 1/2[-1/2(3 - 7/2) + 7(7/2 - 5/2) + 7/2(5/2 - 3)] Area of triangle DEF = 1/2[ 1/4 +7 -7/4] Area of triangle DEF = 22/8 Area of triangle ABC = 4 area of triangle DEF Area of triangle ABC = 4*22/8 Area of triangle ABC = 11
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