已知：\(\sin ^{2}30^{\circ}+\sin ^{2}90^{\circ}+\sin ^{2}150^{\circ}= \dfrac {3}{2}\)；\(\sin ^{2}5^{\circ}+\sin ^{2}65^{\circ}+\sin ^{2}125^{\circ}= \dfrac {3}{2}\)通过观察上述两等式的规律，请你写出一般性的命题 ______ ．