7. If L, M are the feet of the perpendiculars from (2, 4, 5) to xy plane and yz plane respectively, then distance LM is units 1) 9/2 2) 2/2 3) V29 4) 31 8. P, Q, R, S are four points respectively (1, 2, -2), (8,10,11), (1,2,3) and (3,5,7). If x is 29x 400 is the length of the projection of PQ on RS then the value of 10 1) 290 2) 380 3) 470 4) 770 9. The vertices of a triangle are A(2,-1,1), B(1,-3,-5), C(3,-4,-4). The radius of the circle passing through A, B and C is V41 2) 2 V35 3) 2 1) V41 2 10. I'is the in centre of the triangle formed by the points A(0,0,4),B(3,0,4),C(0,4,4). '2'is the length of the median through B. if P =( (2 -9,2 +1, 2 3). then 'IP' = 1) V129 2) V164 3) V204 4) V214 11. If A (3, 2, 0), B(5, 3, 2), C(-9, 6, -3) are three points forming a triangle then the coordinates of a point in which the bisector of ZBAC meets BC are given by 88 57 27 1) 16' 16' 16 38 57 17 2) 16 16 16 -88 -57 -27 3) 16 16 38 57 27 4) 16 16 16 16 12. The vertices of a triangle are A (1,-1,2), B(6,11,2), C(1,2,6) then cos A = 63 36 2) 65 16 3) 65 13 4) 65 65 13. If the direction ratios 1,m,n of the lines satisfy 1-5m+3n =0, 712 +5m2 -3n2 = 0 then the angle between the lines is 7 7 1) cos V84 -1 2) cos 3) cos 112