The point of intersection of the lines drawn from the vertices of any ...
About Direction Cosines and Direction Ratios.
1. If a given line makes angles α, β, γ with positive directions of the axes of x, y and x respectively, then cosα, cosβ, cosγ are called the direction cosines (in short d.c.’s) of the given line.
Direction cosines of a line are generally denoted by l, m, n and are written as [l, m, n]
where r is the distance between the given points.
In particular, the d.c.'s of a line joining a point (a
1, y
1, z
1) to the origin are
4. Direction Cosines satisfy
Thus if the d.r.’s of a line are a,b, c, then the direction cosines of the line are
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The point of intersection of the lines drawn from the vertices of any ...
Explanation:
To understand the solution to this problem, let's first define some terms:
- Let ABCD be a tetrahedron with vertices A, B, C, and D.
- Let E, F, G, and H be the centroids of the opposite faces of the tetrahedron.
- Let P be the point of intersection of the lines AE, BF, CG, and DH.
Using Centroid Theorem:
- The centroid of a triangle divides the median in the ratio 2:1.
- Each of the lines AE, BF, CG, and DH can be considered as medians of the triangles AEF, BFG, CGH, and DHE, respectively.
- Therefore, the point P divides each of these medians in the ratio 2:1.
Dividing each line segment:
- Let's consider the line segment AP.
- Since P divides the line AE in the ratio 2:1, we can say that AP:PE = 2:1.
- Similarly, we can say that BP:PF = 2:1, CP:PG = 2:1, and DP:PH = 2:1.
Using Triangle Similarity:
- Let's consider the triangle ABC.
- Since P divides the line AE in the ratio 2:1, we can say that the triangles APE and ABC are similar.
- By the property of similar triangles, we can say that the ratios of corresponding sides are equal.
- Therefore, AP:AB = PE:BC = 2:1.
- Similarly, we can prove that BP:BC = 2:1, CP:CA = 2:1, and DP:DA = 2:1.
Conclusion:
- From the above analysis, we can conclude that the point P divides each line segment from the vertices of the tetrahedron to the centroids of the opposite faces in the ratio 2:1.
- Therefore, the correct answer is option A) 2:1.
The point of intersection of the lines drawn from the vertices of any ...
About Direction Cosines and Direction Ratios.
1. If a given line makes angles α, β, γ with positive directions of the axes of x, y and x respectively, then cosα, cosβ, cosγ are called the direction cosines (in short d.c.’s) of the given line.
Direction cosines of a line are generally denoted by l, m, n and are written as [l, m, n]
where r is the distance between the given points.
In particular, the d.c.'s of a line joining a point (a
1, y
1, z
1) to the origin are
4. Direction Cosines satisfy
Thus if the d.r.’s of a line are a,b, c, then the direction cosines of the line are