The bases of an isosceles trapezoid are 12 and 42 the side is 39 find the length

The bases of an isosceles trapezoid are 12 and 42 the side is 39 find the length of the diagonal of the trapezoid.

Let ABCD be an isosceles trapezoid: AB = CD = 39 conventional units – sides, AD = 42 conventional units – larger base, BC = 12 conventional units – smaller base, AC = BD – diagonals.
The length of the diagonal of an isosceles trapezoid is found by the formula:
d = √ (ab + c ^ 2),
where a is the length of the larger base, b is the length of the smaller base, c is the length of the lateral side.
Substitute the known values and find the length of AC and BD (d):
d = √ (42 * 12 + 39 ^ 2) = √ (504 + 1521) = √2025 = 45 (conventional units).
Answer: AC = BD = 45 conventional units.