In the figure shown, BC is parallel to AD and AB =
AB = CD. What is the
perimeter of quadrilateral ABCD ?

52 units.

Step-by-step explanation:

If we drop a perpendicular line from point C to AD and call the point ( on AD) E we have a right triangle CED.

Now CE = 6 and as the whole figure is symmetrical about the dashed line,

ED = (26 - 10)/2

= 8.

So by Pythagoras:

CD^2 = 6^2 + 8^2 = 100

CD = 10.

So, as AB = CD,

the perimeter = 10 + 26 + 2(8)

= 52.

f(x)=4

step-by-step explanation: