Respuesta :

Answer:


Step-by-step explanation:

If the upper triangle has a right angle at Island C, we need only use the Pythagorean Theorem to find x:

(10 mi)^2 + (20 mi)^2 = x^2, so that

x^2 = 100 mi^2 + 400 mi^2 = 500 mi^2, which reduces to

x = +10√5 mi

Note that the shortest side (10 mi) is adjacent to a 30 degree angle.  Thus, the upper triangle is a 30-60-90 triangle, meaning that the Pythagorean Theorem DOES apply here.

Next time, please incude ALL of the verbal instructions.  Thank you.