Question

One angle of a rhombus measures 108°, and the shorter diagonal is 9 inches long. Approximately how long is the side of the rhombus? (Hint: Diagonals of a rhombus bisect the angles.) 7 in. 8 in. 11 in.

Answer 1

The value of the length of the rhombus will be found as follows:
cos θ=adjacent /hypotenuse
θ=108/2=54°
adjacent = 9/2=4.5 inch
hypotenuse=length of the rhombus
thus
cos 54=9/x
x=4.5/cos 54
x=7.6558~8  inches
the answer is 8 inches