It seems that all these measurements are correct, so you answer would be e, but I will still show how all the answers are correct.
Answer choice a is relatively easier to show. You are given that angle A = 36 and angle B = 90, and you also know that the sum of the angles of a triangle must sum up to 180, so if you subtract the known angles from 180, you get 180 - 90 - 36 = 54
For answer choice B, you can use the law of sines to show that a = 15.26 as follows...
(a / sin 36) = (21 / sin 54)
When you solve this equation for "a" by multiplying both sides sides of the equation by sin 36, you get that a = 15.26.
Answer choice C can be shown using the Pythagorean theorem since you have a right triangle
√(15.262 + 212) = 25.96
I don't quite understand what Answer choice D is supposed to mean, but if it is for whatever reason a reference to answer choice C, then we have already shown that it is correct, and therefore, your final answer must be E) all of the measurements are correct.
