**Definition of Altitude of a Triangle**

- Altitude of a Triangle is the perpendicular distance from any of its vertices to the opposite side. (This opposite side of the vertex is called the base of the altitude.)

**More about Altitude of a Triangle**

- As a triangle has 3 vertices, it has 3 altitudes.
- Altitudes can be used to find the area of the triangle.

**Example of Altitude of a Triangle**

- In the triangle ABC, AD is the perpendicular distance drawn from vertex A to the side BC. So, AD is the altitude of the triangle.

**Solved Example on Altitude of a Triangle**

Which of the figures shows an altitude of the triangle drawn?

Choices:

A. Figure 1

B. Figure 2

C. Figure 3

D. none of these

Correct Answer: C

Solution:

Step 1:Altitude of a triangle is the perpendicular distance from one of its vertices to its opposite side.

Step 2:The line drawn in Figure 3 from D to EF shows the perpendicular distance between D and EF.

Step 3:So, Figure 3 shows an altitude of the triangle drawn.

**Related Terms for Altitude of a Triangle**

- Altitude
- Base (of a Polygon)
- Distance
- Vertex