Flag Analytical Geometry> A triangle ABC is formed by three lines x...
question mark

A triangle ABC is formed by three lines x+y+2=0,x-2y+5=0 and 7x+y-10=0. P is a point inside the triangle ABC such that areas of the triangles PAB,PBC and PCA are equal. If the co-ordinates of the point P are (a,b) and the area of the triangle ABC is ‘g’​, then find (a+b+g). [P.S. The answer to this question is supposed to be 15.Just tell me how.]

Leafyrito , 8 Years ago
Grade 10
anser 1 Answers
Harsh Hardik

Last Activity: 7 Years ago

To take out the coordinates of A,B and C use the point of intersection of lines
so, coordinates of A come to be x+y=-2 and x-2y=-5 then by using elimination method the coordinates of A come to be (-3,1).
Similarly of B (2,-4) and C (1,3).
Area of triangle ABC
g=1/2[-3(-4-3)+2(3-1)+1(1+4)]
and g comes out to be 15 by using area of triangle.
Now,P is a centroid of the triangle ABC as it divides the triangle into 3 equal areas.
so P(a,b) here x=a and y=b coordinate.
Now, a=x1+x2+x3/3
a=-3+2+1/3=0
similarly of b = 1-4+3/3 = 0
so, a+b+g=0+0+15=15 
hope it is clear!!!
Regards Harsh Hardik
Student of fiitjee
 

Provide a better Answer & Earn Cool Goodies

Enter text here...
star
LIVE ONLINE CLASSES

Prepraring for the competition made easy just by live online class.

tv

Full Live Access

material

Study Material

removal

Live Doubts Solving

assignment

Daily Class Assignments


Ask a Doubt

Get your questions answered by the expert for free

Enter text here...