Question

What is the area of an isosceles trapezoid if the length of an altitude is h, and diagonals are perpendicular to each other?

Answer 1

Suppose the isosceles trapezoid is given by ABCD, where AB║ CD, and the height of trapezoid otherwise called the altitude is, h. 
side AB=a and side CD=d
The area of isosceles trapezoid will be given by;
Area=1/2*height*(a+b) 
Area=1/2*[h(a+b)]