Respuesta :

Like the given triangle is an isosceles triangle, the value of ∠ABC is 72°.

Types of Triangles

There are 3 main classifications for triangles refer to its sides.

  • Equilateral triangle - This triangle presents all sides with the same dimensions and the all angles equal to 60°.
  • Isosceles triangle - This triangle presents two sides with the same dimensions and it has two angles with equal size.
  • Scalene triangle  - This triangle presents all sides with different dimensions and it has all angles no equal size.

The figure shows that the given triangle is an isosceles triangle because it has two equal sides (AB=AC). If it is an isosceles triangle, this triangle presents two sides with the same dimensions (AB=AC). and it has two angles with equal size(∠ACB=∠ABC).

Knowing the sum internal angles of triangle is 180°. You can write:

3x+6x+6x=180

15x=180

x=12

Like ∠ABC=6x, then ∠ABC=6*12=72°.

Read more about the types of triangles here:

https://brainly.com/question/24265179