CLASS-6
TRIANGLE - ISOSCELE TRIANGLE

ISOSCELE TRIANGLE -

An isosceles triangle is a type of triangle that has at least two sides of equal length and consequently, two angles of equal measure. The third side and the third angle are unequal.

Key features of an isosceles triangle:-

1. Side Lengths:- At least two sides of the triangle are of equal length. Mathematically, if AB, BC, and CA are the side lengths of the triangle, then AB = a or BC = b or CA = a.
2. Angles:- The angles opposite the equal sides are also equal. Mathematically, if A, B, and C are the angles opposite sides respectively, then A = B or B = C or C = A.

Here's an illustration of an isosceles triangle:

In the above triangle ABC:-

• Side lengths AB = a and CA = a are equal. So, AB = CA.
• Angle A and Angle C have equal measures.

An isosceles triangle can have different configurations based on which sides are equal, and it can also be classified as a right, obtuse, or acute isosceles triangle based on the measures of its angles.

Isosceles triangles are commonly encountered in geometry, and their properties are often used in various mathematical and practical applications.