In the figure, equalateral triangles are drawn on the sides of a right triangle. The total area of the triangles, based on their sides is A. The size of the grey area is B. The size of the white area is C. Which of the following must be true?
1. a^2 + b^2 = c^2
2. A=C
3. A+B=C
4. A=B
a bit confused with the answers