Multiplying a vector v by a scalar k creates a new vector with magnitude kv. If k is positive, the new vector points in the same direction as v, and if k is negative, it points in the opposite direction of v. The document also reviews trigonometry ratios for right triangles, reminding the reader that the Pythagorean theorem can be used as a2 + b2 = c2 and trig functions like sine, cosine, and tangent can help solve for unknown angles or sides.