A parallelogram has sides of lengths 7 and 4, and one angle is 55°. Find the lengths of the diagonals. (Round your answers to two decimal places. Enter your answers as a comma-separated list.)

Answer 1

use the law of cosines. The short diagonal is

7^2+4^2-2*7*4cos55°

The longer diagonal lies opposite the supplementary angle, so it is

7^2+4^2+2*7*4cos55°