Question

In dreptunghiul ABCD, AB=15 cm, AD=8 cm. Calculati AC si sinusul unghiului BDC.

Answer 1

$BD^2=AD^2+AB^2 \Rightarrow BD= \sqrt{AD^2+AB^2}= \sqrt{8^2+15^2}= \\ \\ = \sqrt{289}=17~(cm). \\ \\ AC=BD=17~cm. \\ \\ sin( \angle BDC) = \frac{BC}{BD}= \frac{8}{17}.$