because there are 12 in one layer and there are 3 layers
Answer:
<h2>x + 2y = 8</h2>
Step-by-step explanation:
The standard form of an equation of a line:

We have:

Convert:
<em>multiply both sides by 2</em>
<em>add x to both sides</em>

Answer:
Right Triangle
Step-by-step explanation:
15² + 20² = 225 + 400 = 625 = 25²