Sarah S. answered 02/07/19
Math help for Geometry, Algebra, Trigonometry and Pre-Calculus
This questions is testing your knowledge of 30-60-90 triangles. A 30-60-90 triangle is an equilateral triangle split in half so the sides have the relationship x, 2x, x(square root of 3) You can use Pythagoras theorem to verify this
The diagonal is the hypotenuse of the triangle making it the longest side so 10 = 2x in your case and x = 5
and the area of your rectangle would be 5 (5 square root of 3) = 25 sq rt 3