HG 47
D26. The area of a SQ is equal to the area of any triangle with which it is associated.
T77. Two SQs have the same area if and only if a summit angle of one equals a summit angle of the other.
D27. The areas of a LQ is equal to the area of any right triangle with which it is associated.
T78. Two LQs have the same areas if and only if their acute angels are equal.