In a rhombus whose side measures 40 and the smaller angle is 28°, find the length of the larger diagonal, to the nearest tenth. explain how you do this. i need to know to answer other questions. i cant figure it out

I found these formulas

Given side length "a" and angle "A", calculate the diagonals
p = square root [( 2a2 - 2a2 cos(A) )]
q = square root [( 2a2+ 2a2 cos(A) )]
Source:
http://www.calculatorsoup.com/calculators/geometry-plane/rhombus.php

short diagonal = p = 19.3535526454

long diagonal = q  = 77.6237077187

38 dollars is your answer.