1980
20
You multiply the width by the length to get square footage. Example 4x8 sheet is 32 sqare feet, 4x12 ft board has 48 square feet.
Assuming it's 4x8 inches, then one brick = 1/3 feet * 2/3 feet, so the area of a brick is 2feet2/9. 120 feet2/(2feet2/9) = 540 bricks
4-ft x 8-ft = 32 square feet in each sheet400/32 = 121/2 sheets
20
324
1980
144
20
96
You multiply the width by the length to get square footage. Example 4x8 sheet is 32 sqare feet, 4x12 ft board has 48 square feet.
Just multiply the two numbers together. This means it covers 32 square feet.
The answer depends on the units used for 4x8 which are unspecified. The answer will vary according to whether those units are inches, metres, parsecs, etc.
For 80 square feet you will need a 360 4" x 8" bricks.
Assuming it's 4x8 inches, then one brick = 1/3 feet * 2/3 feet, so the area of a brick is 2feet2/9. 120 feet2/(2feet2/9) = 540 bricks
4-ft x 8-ft = 32 square feet in each sheet400/32 = 121/2 sheets