Question

Calculati aria paralelogramului ABCD, BC =8,AB =10, măsură unghiului ABC =150​

Answer 1

ABCD paralelogram

$Aria=AB\cdot BC\cdot\sin\angle ABC\\ =10\cdot8\cdot\sin(150^{\circ})\\ =80\cdot\sin(60^{\circ}+90^{\circ})\\ =80\cdot\cos(60^{\circ})\\ =80\cdot\frac{1}{2}\\ =\bold{40\:\: cm²}$