standard_description: Use similar triangles to explain why the slope m is the same between any two distinct points on a non-vertical line in the coordinate plane; derive the equation y = mx for a line through the origin and the equation y = mx + b for a line intercepting the vertical axis at b.
problem_activity: A cube has
$$6$$
equal sides, each with an area of
$${s^2}$$
square units. The surface area of a cube is the total area of all six sides, and is represented by the formula
$$S=6{s^2}$$
.
Find the surface area of a cube with the side lengths below.
a.
$${s=3}$$
inches
b.
$${s=1.2}$$
cm
c.
$${s={2\over3}}$$
ft


aligns: no