Question

Prove cos a = 5/13 pls solve it and no link pls..........​

Answer 1

Answer : The demonstration is below :)

Step-by-step explanation :

We use Pythagoras' theorem :

• In the triangle ABC we have :

AB² = AC² - BC² = 15² - 9² = 144 = 12²

• In the triangle ABD we have :

DB² = AD² - AB² = 13² - 12² = 5²

cos(a) = BD/AD = 5/13