Find side length: right triangle angle is 5 degrees, adjacent side is 15 cm, find diagonal side length

Find side length: right triangle angle is 5 degrees, adjacent side is 15 cm, find diagonal side length


Opposite side / adjacent side = tan5 degree
Opposite side = 15tan5 ° = 1.31cm



Proof: in a right triangle, if a right side is equal to half of the hypotenuse, then the acute angle of the right side is equal to 30 degrees


It is known that in △ ACB, ∠ ACB = 90 ° and AC = 12ab, and it is proved that: take the midpoint D of AB and connect CD, ∵ △ ACB is a right triangle, ∵ ACB = 90 °, ∵ CD = 12ab = ad = BD, ∵ AC = 12ab, ∵ AC = ad = CD, ∵ ACD is an equilateral triangle, ∵ a = 60 °, ∵ B = 180 ° - 90 ° - 60 ° = 30 °