Question

Two islands A and B are 2.0km apart. How far is a third island C from A and from B is angle ACB=90 degrees

Answer 1

$sin (\alpha)=AC/AB$

$AB=\sqrt{AC^2+BC^2}$

BC=AC

$2=\sqrt{2AC^2}$

$4=2AC^2$

$AC=BC=\sqrt2$