Question

Triangle ABC and DEF are right triangles, as shown.Triangle ABC is similar to triangle DEF. which ratios areequal to cos (B)

Answer 1

Take into account that the cosine of an angle is given by:

cos B = length of the adjacent side / hypotenuse

in this case, you have:

length of adjacent side to B = BC

hypotenuse = AB

replace the previous values of the parameters into the formula for cos B:

cos B = BC/AB

Moreover, due to BC and AB are similar to EF and DE respectively, you have for cos B:

cos B = EF/DE