Triangle Centroid Practice Problems & Median Intersection

Master triangle centroid and median intersection with step-by-step practice problems. Learn the 2:1 ratio theorem and solve geometry problems confidently.

📚Practice Triangle Centroid and Median Properties
  • Find the centroid using median intersection points in triangles
  • Apply the 2:1 ratio theorem to solve for median segments
  • Calculate triangle perimeters using median properties and equal side divisions
  • Identify medians and prove centroid locations in geometric problems
  • Solve for unknown lengths using centroid division properties
  • Work with coordinate geometry to find triangle centers and medians

Understanding Parts of a Triangle

Complete explanation with examples

The center of the triangle

  1. All three medians in a triangle intersect at a single point called the centroid -
    If two medians intersect at a point inside the triangle, the third median must pass through it as well.
  2. The intersection point of the medians - the centroid - divides each median in a ratio of 2:12:1 where the larger part of the median is closer to the vertex.

Diagram of a rectangle labeled ABCD with a marked midpoint M at the intersection of its diagonals. The rectangle is black with white and orange highlights, showcasing symmetry and geometry properties.

Detailed explanation

Practice Parts of a Triangle

Test your knowledge with 36 quizzes

In an isosceles triangle, the angle between ? and ? is the "base angle".

Examples with solutions for Parts of a Triangle

Step-by-step solutions included
Exercise #1

Is DE side in one of the triangles?
AAABBBCCCDDDEEE

Step-by-Step Solution

Since line segment DE does not correspond to a full side of any of the triangles present within the given geometry, we conclude that the statement “DE is a side in one of the triangles” is Not true.

Answer:

Not true

Video Solution
Exercise #2

The triangle ABC is shown below.

To which side(s) are the median and the altitude drawn?

AAABBBCCCDDDEEEFFF

Step-by-Step Solution

To solve the problem of identifying to which side of triangle ABC ABC the median and the altitude are drawn, let's analyze the diagram given for triangle ABC ABC .

  • We acknowledge that a median is a line segment drawn from a vertex to the midpoint of the opposite side. An altitude is a line segment drawn from a vertex perpendicular to the opposite side.
  • Upon reviewing the diagram of triangle ABC ABC , line segment AD AD is a reference term. It appears to meet point C C in the middle, suggesting it's a median, but it also forms right angles suggesting it is an altitude.
  • Given the placement and orientation of AD AD , it is perpendicular to line BC BC (the opposite base for the median from A A ). Therefore, this line is both the median and the altitude to side BC BC .

Thus, the side to which both the median and the altitude are drawn is BC.

Therefore, the correct answer to the problem is the side BC BC , corresponding with choice Option 2: BC \text{Option 2: BC} .

Answer:

BC

Exercise #3

Look at triangle ABC below.

What is the median of the triangle and to which side is it drawn?

AAABBBCCCDDDEEE

Step-by-Step Solution

A median of a triangle is a line segment that connects a vertex to the midpoint of the opposite side. In triangle ABC \triangle ABC , we need to identify such a median from the diagram provided.

Step 1: Observe the diagram to identify the midpoint of each side.

Step 2: It is given that point E E is located on side AC AC . If E E is the midpoint of AC AC , then any line from a vertex to point E E would be a median.

Step 3: Check line segment BE BE . This line runs from vertex B B to point E E .

Step 4: Since E E is labeled as the midpoint of AC AC , line BE BE is the median of ABC \triangle ABC drawn to side AC AC .

Therefore, the median of the triangle is BE BE for AC AC .

Answer:

BE for AC

Exercise #4

Look at triangle ABC below.

Which is the median?

αααAAABBBCCCDDDEEE

Step-by-Step Solution

To solve this problem, we must identify which line segment in triangle ABC is the median.

First, review the definition: a median in a triangle connects a vertex to the midpoint of the opposite side. Now, in triangle ABC:

  • Point A represents the vertex.
  • Point E lies on line segment AB.
  • Line segment EC needs to be checked to see if it connects vertex E to point C.

From the diagram, it appears that E is indeed the midpoint of side AB. Thus, line segment EC connects vertex C to this midpoint.

This fits the definition of a median, verifying that EC is the median line segment in triangle ABC.

Therefore, the solution to the problem is: EC \text{EC} .

Answer:

EC

Exercise #5

Look at the triangle ABC below.

AD=12AB AD=\frac{1}{2}AB

BE=12EC BE=\frac{1}{2}EC

What is the median in the triangle?

AAABBBCCCEEEDDD

Step-by-Step Solution

A median in a triangle is a line segment connecting a vertex to the midpoint of the opposite side. Here, we need to find such a segment in triangle ABC \triangle ABC .

Let's analyze the given conditions:

  • AD=12AB AD = \frac{1}{2}AB : Point D D is the midpoint of AB AB .
  • BE=12EC BE = \frac{1}{2}EC : Point E E is the midpoint of EC EC .

Given that D D is the midpoint of AB AB , if we consider the line segment DC DC , it starts from vertex D D and ends at C C , passing through the midpoint of AB AB (which is D D ), fulfilling the condition for a median.

Therefore, the line segment DC DC is the median from vertex A A to side BC BC .

In summary, the correct answer is the segment DC DC .

Answer:

DC

Frequently Asked Questions

What is the centroid of a triangle and how do you find it?

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The centroid is the intersection point where all three medians of a triangle meet. To find it, draw medians from each vertex to the midpoint of the opposite side - they will all intersect at one point, which is the centroid.

How does the centroid divide each median in a triangle?

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The centroid divides each median in a 2:1 ratio, where the longer segment is always closer to the vertex. If a median has length 9, the centroid splits it into segments of length 6 (vertex side) and 3 (base side).

What are the key properties of triangle medians I need to remember?

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Key median properties include: 1) A median connects a vertex to the midpoint of the opposite side, 2) All three medians intersect at the centroid, 3) The centroid divides each median in a 2:1 ratio, 4) Medians divide the triangle into six smaller triangles of equal area.

How do you solve triangle centroid problems step by step?

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Follow these steps: 1) Identify which segments are medians, 2) Locate the centroid where medians intersect, 3) Apply the 2:1 ratio to find unknown segments, 4) Use the fact that medians bisect opposite sides to find equal segments, 5) Calculate perimeters or areas as needed.

Why do all three medians of a triangle always meet at one point?

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This is a fundamental theorem in geometry. If two medians intersect at a point inside the triangle, the third median must pass through that same point. This intersection point is called the centroid and represents the triangle's center of mass.

What's the difference between centroid, circumcenter, and incenter of a triangle?

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The centroid is where medians meet and divides them 2:1. The circumcenter is where perpendicular bisectors meet and is equidistant from vertices. The incenter is where angle bisectors meet and is equidistant from all sides.

How do you find the perimeter of a triangle using median properties?

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Use the fact that medians bisect opposite sides to create equal segments. If you know some side lengths from median endpoints, you can determine the full sides since medians create midpoints. Add all three complete side lengths for the perimeter.

What are common mistakes students make with triangle centroid problems?

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Common errors include: confusing the 2:1 ratio direction (remember the longer part is toward the vertex), not recognizing that medians create equal segments on opposite sides, and mixing up different triangle centers like centroid vs circumcenter.

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