The surface area of an open-top box with length \( L \), width \( W \), and height \( H \) can be found using the formula: \( A=2 L H+2 W H+L W \) Find the surface area of an open-top box with length 9 cm , width 6 cm , and height 7 cm .

Given the formula for the surface area of an open-top box: \[ A = 2LH + 2WH + LW \] we substitute \( L = 9 \) cm, \( W = 6 \) cm, and \( H = 7 \) cm. 1. Calculate \( 2LH \): \[ 2LH = 2(9)(7) = 2(63) = 126 \text{ cm}^2 \] 2. Calculate \( 2WH \): \[ 2WH = 2(6)(7) = 2(42) = 84 \text{ cm}^2 \] 3. Calculate \( LW \): \[ LW = 9 \times 6 = 54 \text{ cm}^2 \] 4. Add these results to find the total surface area: \[ A = 126 + 84 + 54 = 264 \text{ cm}^2 \] Thus, the surface area of the open-top box is \( 264 \) cm\(^2\).