Answer:
The segment that extends from the vertex of a triangle to the opposite side and is perpendicular to the side of the triangle is called the altitude.
Explanation:
Please find the attachment.
We have been given an incomplete statement. We are supposed to complete the given statement.
Statement: The segment that extends from the vertex of a triangle to the _____ side and is perpendicular to the side of the triangle is called the altitude.
By the definition of altitude, an altitude of a triangle is a line segment from a vertex that is perpendicular to the opposite side.
Therefore, the correct word for our given statement would be "opposite".