The mean of 22.3 19.7 25.4 and another number is 23.4 find the missing number

In djkl, side jk measures 10.6 inches, side kl measures 7 inches, and side jl measures 5 inches. based on the information that is provided, which could be a correct set of angle measures for these sides? angle j = 23.2°, angle k = 33.5°, angle l = 23.2° angle j = 23.2°, angle k = 33.5°, angle l = 123.2° angle j = 123.2°, angle k = 23.2°, angle l = 33.5° angle j = 33.5°, angle k = 23.2°, angle l = 123.2°

Me, prove a quadrilateral with vertices g(1,-1), h(5,1), i(4,3) and j(0,1) is a rectangle using the parallelogram method and a rectangle method.

Solve for n? [tex]z = \frac{3}{4} mn[/tex]