+308 What is the perimeter, in cm, of quadrilateral ABCD if *(imagine line over)AB is perpendicular to BC*, DC is perpendicular to BC, AB = 9 cm, DC = 4 cm, and BC = 12 cm?
+129849 See the following :
Let A = (0, 0)
B= (9, 0)
C = (9, 12)
D = (5, 12)
We already know AB , BC and DC
So we just need to find the distance between A and D
Using the distance formula we have
AD = sqrt [ ( 5 - 0)^2 + (12 - 0)^2 ] = sqrt [ 25 + 144] =sqrt (169) = 13
So the perimeter = 9 + 12 + 4 + 13 = 38 units
