13. In AABC, equation of BC is x-y =0. If the circumcentre and orthocenter are (2,3).(5,8). then the circumradius is 14. The number of integral points (both coordinates should be integers) exactly in the Interior of the triangle with vertices (0.0).(0, 21) and (21.0) is 1)133 190 3)233 4)105 15. The line +-1 meets y -axis and x-axis at A.B respectively. A square ABCD is constructed on the line segment AB away from the origin. The coordinates of the vertex of the square farthest from origin are 1)(7.3) 4.7) 3)(6,4) 4(3.4) 16. If x-2y+4=0 and 2x +y-5=0 are the sides of an isosceles triangle having area 10 sq. units then the equation of the third side is 113x - y=-9 17. Let P be (5,3) and Ron y -x and O on the x-axis be such that PQ + QR + RP is 2)3x - y+11=0 3) x - 3y = 19 4)3x - y+15 =0 minimum. Then the coordinates of O are 2)(17,0) 4)(5,0) 18. Let m is slope of line joining the points A and B. point A, (x,y,).A,(x.y) A, (s,-y) are such that x.x , are in APand Y,.Y y, are also in AP. then m m, t.m is equal to 1)0 2)(n-1)m 3) nm 4)n' m 19. Aray of light is sent along the line x-2y-3=0 on reaching the line 3x - 2y -5 =0 the ray is reflected from it, then the equation of the line containing the reflected ray 1)2x - 29y - 31 = 0 29x - 2y -31=0 4)31x - 3y +34 =0 3)3x -3ly + 34 = 0