When two lines cross to form an X shape, the opposite pairs of angles are known as vertical angles. They are always congruent to one another.
They do not have to be vertically aligned (meaning the angles could be sitting side by side). Example: In problem 15, angle 1 and angle 3 are vertical angles that are congruent.
<span>The correct equation is $50(0.80). The discount is 20% or 0.20, so we multiply the original price by 1-(discount), which is 1-0.2, so we multiply by 0.80.</span>
