Answer: Acute Triangle
Explanation:
An orthocenter of a triangle is a point where all the three altitudes of the triangle intersect .
- If the triangle is acute, then its orthocenter lie inside the triangle.
- If the triangle is right, then its orthocenter lie on the vertex opposite the hypotenuse.
- If the triangle is obtuse, then its orthocenter lie outside the triangle.
Therefore, if an orthocenter lies inside of a triangle, then the triangle must be an acute triangle.