Three Dimensional Geometry

Let the vertices Q and R of the triangle PQR lie on the line x+35 = y-12 = z+43, QR = 5 and the coordinates of the point P be (0, 2, 3). If the area of the triangle PQR is mn then :

1. 2m - 5 21 n = 0
2. m - 5 21 n = 0
3. 5m - 21 2 n = 0
4. 5m - 2 21 n = 0

If the image of the point P(1, 0, 3) in the line joining the points A(4, 7, 1) and B(3, 5, 3) is Q( , , ), then + + is equal to :

1. 463
2. 18
3. 13
4. 473

The line L1 is parallel to the vector a = -3 i + 2 j + 4 k and passes through the point (7, 6, 2) and the line L2 is parallel to the vector b = 2 i + j + 3 k and passes through the point (5, 3, 4). The shortest distance between the lines L1 and L2 is :

1. 23 38
2. 21 38
3. 23 57
4. 21 57

Let L1 : x-11 = y-2-1 = z-12 and L2 : x+1-1 = y-22 = z1 be two lines. Let L3 be a line passing through the point ( , , ) and be perpendicular to both L1 and L2. If L3 intersects L1, then |5 - 11 - 8 | equals :

1. 25
2. 20
3. 16
4. 18

Let a = i + 2 j + k and b = 2 i + 7 j + 3 k. Let L1 : r = (- i + 2 j + k) + a, R and L2 : r = ( j + k) + b, R be two lines. If the line L3 passes through the point of intersection of L1 and L2 and is parallel to a + b, then L3 passes through the point :

1. (-1, -1, 1)
2. (2, 8, 5)
3. (8, 26, 12)
4. (5, 17, 4)

Let a straight line L pass through the point P(2, -1, 3) and be perpendicular to the lines x-12 = y+11 = z-3-2 and x-31 = y-23 = z+24. If the line L intersects the yz-plane at the point Q, then the distance between the points P and Q is:

1. 10
2. 2
3. 2 3
4. 3

Let P be the foot of the perpendicular from the point (1,2,2) on the line L: x-11= y+1-1= z-22. Let the line r= (- i+ j-2 k )+ ( i- j+ k ), , intersect the line L at Q. Then 2(PQ)2 is equal to :

1. 25
2. 27
3. 19
4. 29

If the image of the point (4, 4, 3) in the line x - 12 = y - 21 = z - 13 is ( , , ), then + + is equal to

1. 12
2. 9
3. 7
4. 8

The square of the distance of the point ( 157, 327, 7 ) from the line x+13 = y+35 = z+57 in the direction of the vector i + 4 j + 7 k is:

1. 66
2. 54
3. 41
4. 44

Let in a ABC, the length of the side AC be 6, the vertex B be (1,2,3) and the vertices A, C lie on the line x-63= y-72= z-7-2. Then the area (in sq. units) of ABC is:

1. 42
2. 17
3. 56
4. 21