Question

problem 10: select the altitude of △abc from vertex b.

Explanation:

Step1: Recall altitude definition

The altitude of a triangle from a vertex is a perpendicular line segment from that vertex to the opposite side.

Step2: Identify opposite side

For vertex B of $\triangle ABC$, the opposite side is AC.

Step3: Look for perpendicular

We need to find the option that shows a line segment from B perpendicular to AC.

Answer:

The altitude from vertex B of $\triangle ABC$ is the line segment drawn from vertex B perpendicular to the opposite - side (extended if necessary). Without seeing the actual options in detail, the correct option would be the line segment that is perpendicular from B to the line containing AC.