The sum of the 3 exterior angles of an equilateral triangle add up 360 degrees
in a regular (equilateral) triangle, all angles are 60 degrees, to add up to 180
The 3 interior angles of 60 degrees add up to 180 degrees
The interior angles of a square or any rectangle add up to 360 degrees.
if you're referring to the sum of the interior angles, it's 180 degrees, as is with any kind of triangle.
the sum of angles in an equilateral triangle add up to 180 degrees
The 4 interior right angles inside a square add up to 360 degrees
The 4 interior right angles inside a square add up to 360 degrees
Any number you can add up to get the sum
The interior angles will add up to 180 degrees in this equilateral triangle
The 3 interior angles of this equilateral triangle will add up to 180 degrees
When you add up the answer you get in the end is called the 'sum'.