Step-by-step explanation:
In an equilateral triangle, all the three sides are equal as well as all the angles are equal. Let the angles be x.
We know that the sum of angles of a triangle is equal to 180 degrees. It means that,
x+x+x=180
3x=180
x=60°
Hence, if a triangle is an equilateral triangle, then the triangle has exactly three 60° angles. Hence, △ABC is an equilateral triangle
-105
Multiply first, then subtract, then add.
