Question 1101004
The sides of a triangle are given by the lines 2x-y+3=0, x-2y-3=0 and 2x+y-11=0. Find the area of the triangle.
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the lines 
2x-y+3=0 --> y = 2x + 3
x-2y-3=0 --> y = (1/2)x - 3/2
2x+y-11=0 --> y = -2x + 11
Find the 3 vertices, then the 3 lengths.
The 2nd & 3rd lines are perpendicular, so it's a right triangle.
Area = b*h/2