Question

ABC is a triangle in which angle C is a right angle. If the coordinates of A and B be (–3, 4) and (3, –4) respectively, then the equation of the circumcircle of triangle ABC is.

• A. $x ^ { 2 } + y ^ { 2 } - 6 x + 8 y = 0$
• B. $x ^ { 2 } + y ^ { 2 } = 25$
• C. $x ^ { 2 } + y ^ { 2 } - 3 x + 4 y + 5 = 0$
• D. None of these

Answer 1

Answer: (B)

$x ^ { 2 } + y ^ { 2 } = 25$

Answer 2

AB must be diameter because semi-circle subtends right angle to circumference. Therefore, find the equation of circle as the line joining the points $A ( - 3,4 )$ and $B ( 3 , - 4 )$ as diameter.