Question

rhombus has sides of length 10 cm. and the angle between two adjacent sides is 76 degrees. Find the lengths of the other diagonal.

Answer 1

Let the length of one of the diagonals be 2x and the other be 2y, then
cos (76/2) = x/10
x = 10 cos 38 = 7.88 cm

sin (76/2) = y/10
y = 10 sin 38 = 6.16 cm