In triangle geometry, the three medians of a triangle intersect at a single special point. This common point of intersection of all three medians is called the triangle's what?
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Aorthocentre
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Bincentre
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Ccentroid
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Dcircumcentre
Answer
Correct Answer: centroid
Explanation
Introduction / Context: This is a conceptual geometry question that tests your knowledge of special points associated with a triangle. Each of the four classical centres (centroid, orthocentre, incentre, and circumcentre) is defined in a different way. Here we focus specifically on medians and their point of concurrency.
Given Data / Assumptions:
- We are dealing with a general triangle (no special type assumed).
- Each median connects a vertex to the midpoint of the opposite side.
- All three medians intersect in a single point.
- We must identify the correct name for this point.
Concept / Approach: It helps to recall the definitions: Centroid: Intersection point of the three medians. Orthocentre: Intersection point of the three altitudes. Incentre: Intersection point of the three internal angle bisectors. Circumcentre: Intersection point of the perpendicular bisectors of the sides. Recognising which construction is described in the question immediately leads to the correct term.
Step-by-Step Solution: The question explicitly mentions medians. By definition, medians connect each vertex to the midpoint of the opposite side. The unique point at which all three medians of a triangle meet is called the centroid. Therefore, the point of intersection of all the three medians is the centroid.
Verification / Alternative check: In coordinate geometry, if the vertices of a triangle are (x1, y1), (x2, y2), and (x3, y3), the intersection of the medians is at the point whose coordinates are: ((x1 + x2 + x3) / 3, (y1 + y2 + y3) / 3) This point is well known as the centroid and lies two-thirds of the way from each vertex along the median, supporting our identification.
Why Other Options Are Wrong: Orthocentre involves altitudes, not medians. Incentre uses angle bisectors, and circumcentre uses perpendicular bisectors of the sides. None of these definitions match the description given in the question.
Common Pitfalls: Students sometimes mix up the various triangle centres because their names sound similar. The key is to link each centre with its defining construction: medians for centroid, altitudes for orthocentre, and so on. Drawing a simple triangle and sketching the lines helps fix the concept visually.
Final Answer: The point of intersection of all the medians is called the centroid of the triangle.