- Books Name
- CBSE Class 7 Mathematics Book
- Publication
- Param Publication
- Course
- CBSE Class 7
- Subject
- Mathmatics
Triangle
A triangle is a closed figure made by three line segments. It has three vertices, three sides and three angles.
A triangle ABC is given having three vertices A, B, C and three sides AB, BC, CA and three angles are ∠ABC, ∠ BCA, ∠CAB.
Classification of triangles:
1. With respect to angles are:
(a) Acute-angled triangles
(b) Obtuse-angled triangles
(c) Right-angled traingles
(a) Acute-angled triangles
A triangle in which measurement of each of the three angles are less than 90°.
(b) Obtuse-angled triangle :
A triangle in which one angle is obtuse angle i.e. greater than 90° but less then 180°.
(c) Right-angled triangle:
A triangle in which one angle is exactly 90°.
• The side opposite to the right angle is called the hypotenuse.
• The other two sides are called as the legs of the right-angled triangle (or base and perpendicular).
• In the given figure AC is the hypotenuse and AB and BC are the legs of DABC.
- Books Name
- class 7 Mathematics Book
- Publication
- ReginaTagebücher
- Course
- CBSE Class 7
- Subject
- Mathmatics
Chapter 6
Triangle and its properties
Median of a triangle
Median of a triangle is a line segment joining a vertex to the midpoint of the opposing side, bisecting it.
A median connects a vertex of a triangle to the mid-point of the opposite side.
In the ∆ ABC, the line segment AD joining the mid-point of BC to its opposite vertex A is called a median of the triangle.
Properties of Median of a Triangle
Every triangle has exactly three medians one from each vertex and they all intersect each other at the triangle's centroid.
- The 3 medians always meet at a single point, no matter what the shape of the triangle is.
- The point where the 3 medians meet is called the centroid of the triangle. Point O is the centroid of the triangle ABC.
- Each median of a triangle divides the triangle into two smaller triangles which have equal area.
- In fact, the 3 medians divide the triangle into 6 smaller triangles of equal area.
In ∆ ABC, three medians are AD, CE and BF and they are intersecting the point O which is centroid of the triangle.