Question

1. each edge of a cube is 6 cm. surface area? a) 36 cm² b) 72 cm² c) 144 cm² d) 216 cm²

Explanation:

Step1: Recall surface - area formula

The surface - area formula of a cube is $S = 6a^{2}$, where $a$ is the length of the edge of the cube.

Step2: Substitute the value of $a$

Given $a = 6$ cm. Substitute $a = 6$ into the formula: $S=6\times6^{2}$.

Step3: Calculate the result

First, calculate $6^{2}=36$, then $6\times36 = 216$ $cm^{2}$.

Answer:

D. $216$ $cm^{2}$