Availability, in the context of a computer system, refers to the ability of a user to access information or resources in a specified location and in the correct format.
Defined, the triangle proportionality theorem states that if you draw a line parallel to one of the sides of a triangle that also crosses the other two sides, then that line will divide the two sides in a proportional way.
And then there's the hypotenuse leg theorem, or HL theorem. This theorem states that 'if the hypotenuse and one leg of a right triangle are congruent to the hypotenuse and one leg of another right triangle, then the triangles are congruent.'. This is kind of like the SAS, or side-angle-side postulate. But SAS requires you to know two sides and the included angle.