Difficulty: Easy
Correct Answer: outside the triangle
Explanation:
Introduction / Context:
This conceptual geometry question tests your knowledge of the orthocentre, which is the point of intersection of the altitudes of a triangle. The location of the orthocentre depends on the type of triangle: acute, right angled, or obtuse angled.
Given Data / Assumptions:
Concept / Approach:
The position of the orthocentre varies with the nature of the triangle. In an acute triangle, all angles are less than 90 degrees, and the orthocentre lies inside. In a right angled triangle, the orthocentre coincides with the right angled vertex. In an obtuse triangle, at least one altitude must be drawn outside the triangle by extending a side, and the intersection of the altitudes therefore lies outside the triangle.
Step-by-Step Solution:
Verification / Alternative check:
Compare this with the known facts: in an acute triangle, all angles are small, so altitudes intersect inside. In a right angled triangle, two altitudes lie along sides and meet at the right angle vertex. This pattern confirms that only for an obtuse angled triangle does the orthocentre fall outside.
Why Other Options Are Wrong:
Inside the triangle refers to the case for acute triangles, not obtuse triangles. On one side or on a vertex are special positions for right angled triangles. The option none of these is incorrect because one of the specific given statements, outside the triangle, is correct.
Common Pitfalls:
Many learners confuse the orthocentre with the circumcentre or centroid, whose positions behave differently. Others assume all special points must lie inside the triangle, which is not true for obtuse triangles.
Final Answer:
For an obtuse angled triangle, the orthocentre lies outside the triangle.
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