Trigonometric ratios are sine, cosine, and tangent (opposite side over hypotenuse, adjacent side over hypotenuse, and opposite side over adjacent side, respectively); if you wanted to prove that one of the angles of the triangle is 90º, then the cosine of that angle would be 0, the sine would be 1, and the tangent would be undefined.
3/5×9
(3×9)/5
27/5=25/5+2/5
5 2/5
5.4 miles
Its 20 the sides are equal
