L1=3x+4y=5=m=−3/4
L2=4x−3y=5=m=4/3
L3=3x+4y=−5=m=−3/4
L4=4x−3y=−5=m=4/3
Diagonal Ac = 1/5+1/57/5+7/5=2/514/5=17
DiagonalBD=7/5+7/5−1/5−1/5=14/5−2/5=−7
MAC×MBD=17×−7
Diagonals are at right angle
ABCD is a square
Find the equation of circle circumscribing the quadrilateral formed by four lines 3x + 4y − 5 = 0, 4x − 3y − 5 = 0, 3x + 4y + 5 = 0 and 4x − 3y + 5 = 0