Yes, the area of a triangle is base times height over 2. The base is a side of your choice and the height is measured in a right angle to it (You may have to extend it in a straight line).
Lets split the flag into two triangles from corner to corner and consider the bottom right one (the other works the same way).
Chose the edge on the right flag edge as the base and the height of the triangle becomes the width of the flag.
All the colored triangles have the same height and by the look of it roughly the same base length.
Yes, the area of a triangle is base times height over 2. The base is a side of your choice and the height is measured in a right angle to it (You may have to extend it in a straight line).
Lets split the flag into two triangles from corner to corner and consider the bottom right one (the other works the same way).
Chose the edge on the right flag edge as the base and the height of the triangle becomes the width of the flag.
All the colored triangles have the same height and by the look of it roughly the same base length.
Therefore the areas are equals.
I salute your work, we worked it out below :)