How many altitudes does a triangle have?

An altitude of a triangle is a line segment that starts from the vertex and meets the opposite side at right angles.

Since a triangle has three sides and three vertices, it has three altitudes.

Explanation:

An altitude of a triangle is a perpendicular line segment drawn from a vertex to the opposite side (or its extension). Since a triangle has three vertices, you can draw one altitude from each vertex, making a total of three altitudes.

• In an acute triangle, all three altitudes lie inside the triangle.
• In a right triangle, two altitudes coincide with the sides of the triangle that form the right angle.
• In an obtuse triangle, one or two altitudes may lie outside the triangle.