Need step by step find the missing side

Step-by-step explanation:

Let AB=16,BC=5,CD=x,DA=18

BC and DA are perpendicular to CD

Draw a line from B parallel to CD intersecting DA at E.

As BCDE is a rectangle(all angles of quadrilateral=90)

Therefore BE=CD=x and ED=BC=5(opposite sides are equal in a rectangle)

⇒AD=AE+ED

18=AE+5

AE=13

⇒ By Pythogores theorem in right angled triangle ABE

x=

the answer is b.

step-by-step explanation:

by the trigonometric ratio tangent, tangent equals opposite divided by adjacent.

therefore, tan(50) equals ac/3

multiply each side by 3 to get: ac=3tan(50)

the answer is b.