Please see the pic, I'd solved in it.
Answer:
x=4
Step-by-step explanation:
f(x) =1/4 x - 2 when f(x) = -1.
-1=1/4x-2
-1+2=1/4 x
1×4=x
x=4
A rhombus diagonals form right angles. The diagonals also cut in half the angles
use cosine: cos38 =
a = 20cos38
a=15.8