(34×2)+(72×2)
34×2=68
72×2=144
68+144=212
the dimension of the sewing room is 212 square feet
11
•——-•——•
C D E
9 2
Because the line CE is 11, you will need to subtract it by 9 to find line DE.
11-9=2
To check your work you may add 9 and 2 to find out if it comes out to 11 and it does.