If P,Q,R are mid-points of sides of ΔABC then 4×Area(ΔPQR)=Area(ΔABC)
Area of ΔABC=4×21∣C1C2C3∣a1a2a3b1b2b3c1c2c3∣2∣
Where C1,C2,C3 are cofactors ofc1,c2,c3
ΔABC=4×21∣(−1)(3)(−1)∣112−1−2−51311∣2∣
=2×9÷3
=6
JEE Main 2021 — Mathematics Coordinate Geometry
Let the points of intersections of the lines x−y+1=0,x−2y+3=0 and 2x−5y+11=0 are the mid points of the sides of a triangle ABC. Then the area of the triangle ABC is
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