- Books Name
- CBSE Class 7 Mathematics Book

- Publication
- Param Publication

- Course
- CBSE Class 7

- Subject
- Mathmatics

**ALTITUDES OF A TRIANGLE AND ORTHOCENTRE**

AD is a line segment which is perpendicular to the side BC of *∆*ABC .This line segment AD is called as altitude of *∆*

Altitude is also called as height of a triangle. In the given figure AD is the height of *∆ *ABC from vertex A to side BC.

• Orthocentre is the meeting point of all three altitudes of a triangle.

• In the given figure H is the orthocentre of *∆ *ABC.

• In obtuse-angled triangle the orthocentre lies outside the triangle.

• In Acute-angled triangle the orthocentre lies inside the triangle.

• In a Right-angled triangle, the right angle lies at the vertex at which the right angle is formed.

- Books Name
- class 7 Mathematics Book

- Publication
- ReginaTagebücher

- Course
- CBSE Class 7

- Subject
- Mathmatics

**Exterior angles of a triangle**

An exterior angle of a triangle is equal to the sum of the opposite interior angles.

In the above figure, ∠ACD is the exterior angle of the Δ ABC.

So, ∠ACD = ∠CAB + ∠CBA

At each vertex of a triangle, an exterior angle of the triangle may be formed by extending one side of the triangle.