Answer:
d = √347
Explanation:
You can use Pythagoras' theorem twice to determine the length of the diagonal.
Consider the isosceles trapezoid PQRS in the diagram below.
ST = ½(19 - 13) = ½ × 6 = 3
∆PST is a right triangle
∴ PT² + 3² = 10²
PT² = 10² - 3² = 100 - 9 = 91
∆PRT is a right triangle.
∴ PR² = RT² + PT²
PR² = 16² + 91 = 256 + 91 = 347
PR = √347
The length of the diagonal is √347