You will find the area of the 5 surfaces made of glass. There is a front, back, 2 sides, and the bottom. Each face is in the shape of a rectangle, so you will multiply the length by the width. 1. Front- 24 x 27 =648 Back-24 x 27 = 648 2. Side- 21 x 27 =567 Side - 21 x 27 = 567 3. Bottom - 21 x 24 = 504
Add all these together for your total amount of glass needed. The answer is 2934 square cm of glass.