The rectangle with the corners (0,0) (7,0) (0,4) and R has the area:
7*4=28
Now you need to deduct the area of the three triangles that are part of this rectangle and surround PQR
Triangle 1 (0,0),P,Q
(4*3)/2 = 6
Triangle 2: (7,0),R,P
(4*3)/2 = 6
Triangle 3:
(7*1)/2 = 3.5
28-6-6-3.5= 12.5 (Ans A)
geometry
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manulath
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including the both axis, it forms a trapezoid
deduct the area of two triangle from the area of trapezoid.
METHOD II: CO-ORDINATE
by quick glance you can see that both triangles are 3-4-5 triangles
hence two sides are 5 each
also the lines are perpendicular to each other (can be verified by the slopes)
hence you have base and height of a rt. angled triangle
area = 12.5
deduct the area of two triangle from the area of trapezoid.
METHOD II: CO-ORDINATE
by quick glance you can see that both triangles are 3-4-5 triangles
hence two sides are 5 each
also the lines are perpendicular to each other (can be verified by the slopes)
hence you have base and height of a rt. angled triangle
area = 12.5
