In the diagram below of triangle TEM, medians line TB, line EC and line MA intersect at A, and TB = 9. Find the length of TD.

And exactly where is D?

To find the length of TD, we need to use the fact that the point where the medians of a triangle intersect divides each median into segments in a 2:1 ratio.

In this case, the point of intersection of medians TB, EC, and MA is point A. Let's label the segments as follows:

AC = 2x
AM = x
TD = y

Since line TB is a median, it is divided into two segments with a 2:1 ratio. Therefore, we can write the following equation:

TA/TM = 2x/x

Since TA = 2x and TM = x, we can replace them in the equation:

2x/x = 2

Simplifying the equation, we get:

2 = 2

This equation is always true, indicating that our assumption about the segments being in a 2:1 ratio is correct.

Since TB = 9, the segment TM is 1/3 of TB:

TM = (1/3) * 9 = 3

Since AM = x, we know that AM = 3, which means that the segment MD is also 3.

Applying the 2:1 ratio, we can write the equation:

DM/MB = 2/1

Since DM = 3 and MB = y, we can replace them in the equation:

3/y = 2/1

Cross-multiplying and solving for y, we get:

2y = 3
y = 3/2
y = 1.5

Therefore, the length of TD is 1.5.

To find the length of TD, we need to use the properties of medians in a triangle.

In triangle TEM, the medians line TB, line EC, and line MA intersect at point A. According to the property of medians, the point of intersection (A) divides each median into two equal segments, where the segment from the vertex to the point of intersection is twice as long as the other segment.

Given that TB = 9, it means that TA = 2 * AD. Let's denote the length of AD as x.

Using this information, we can set up the following equation:

TA = 2 * AD
9 = 2 * x

Dividing both sides of the equation by 2, we get:

x = 4.5

Therefore, the length of TD (which is equal to x) is 4.5.