The perimeter of the triangle with vertices at (1,0,0), (0,1,0) and (0,0,1) is

The distance between the points (1,4,5) and (2,2,3 ) is

A straight line which makes an angle of 60^o with each of y and z-axes, this line makes with x-axes at an angle

If the direction cosines of two lines are such that l + m + n = 0, l² + m²-n² = 0, then the angle between them is

If a line makes angles ,β,Υ and with four diagonals of a   cube, then the value of     is

Let O be the origin and P be the point at a distance 3 units from origin.If direction ratios of OP are (1,-2,-2) then coordinates of P is given by

The xy - plane divides the line joining the points (-1,3,4) and (2,-5,6)

If P (x,y,z) is a point on the line segment joining Q (2,2,4) and R (3,5,6) such that the projections of OP on the axes are

respectively, then P divides QR in the ratio

A  line makes an obstuse angle with the positive x-axis and angle with the positive y and z-axes respectively.

Its direction cosine are

If projection of a line on x, y and z-axes are 6,2 and 3 respectively, then direction cosines of the line is