## vertex angle of an isosceles triangle

### In an isosceles triangle, the vertex angle is the angle formed at the vertex of the triangle where the two equal sides meet

In an isosceles triangle, the vertex angle is the angle formed at the vertex of the triangle where the two equal sides meet. This angle is also known as the base angle.

Let’s denote the vertex angle as “x”. Since an isosceles triangle has two equal sides, the base angles (or vertex angles) are also equal. Therefore, we can denote the other two base angles as “y” as well.

In an isosceles triangle, the sum of all three angles is always 180 degrees. Since the vertex angle and the base angles are equal, we can express this as:

x + y + y = 180 degrees

Simplifying this equation, we get:

x + 2y = 180 degrees

We know that the base angles are equal, so we can substitute “y” with “x” in the equation:

x + 2x = 180 degrees

Combining like terms:

3x = 180 degrees

Dividing by 3 on both sides:

x = 60 degrees

Therefore, the vertex angle (or base angle) of an isosceles triangle is equal to 60 degrees.

## More Answers:

Exploring the Properties and Formulas of Equilateral Triangles: Side Lengths, Heights, Angles, and More!Exploring Isosceles Triangles: Finding the Lengths of the Legs

How to Find the Base of an Isosceles Triangle: Methods and Formulas