Question

Need help step by step find the missing side thanks

Answer 1

`√(87)`

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

`AB^(2) =BE^(2) +EA^(2)`

`16^(2) =x^(2) +13^(2)`

`x^(2) =256-169`

x=
`√(87)`