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.
An equilateral triangle is an isosceles triangle as it has 2 lengths that are equal and 2 equal sized angles. An isosceles triangle does not necessarily have to have equal lengths and angles do not have to be 60 degrees. So an equilateral triangle is an isosceles triangle but an isosceles triangle may not always be an equilateral triangle.