Step 1:Do length×Width which will be 30×20.That equals 600.
Step 2:Do height times width which is 15×20.That equals 300.
Step 3:Do length times height which is 30×15.That equals 450.
Step 4:Do 600+300+450 which comes out to 1,350.
Step 5:Do 2×1,350 which equals 2,700.
So that means 2,700 will be the answer.