Are the two triangles below similar? Yes, because the corresponding sides are proportional
O No, because the corresponding sides are not proportional
Yes, because there are two pairs of congruent corresponding angles
No, because there are not two pairs of congruent corresponding angles

All per-unit concepts rely on ratios, meaning, to provide a type of measurement

There are three bags: a (contains 2 white and 4 red balls), b (8 white, 4 red) and c (1 white 3 red). you select one ball at random from each bag, observe that exactly two are white, but forget which ball came from which bag. what is the probability that you selected a white ball from bag a?

Use the given information to determine the exact trigonometric value.