Triangle ABC is an equilateral triangle with side lengths labeled a, b, and c. Triangle A B C is an equilateral triangle. The length of side A B is c, the length of B C is a, and the length of A C is b.

Trigonometric area formula: Area = One-half a b sine (C)

Which expressions represent the area of triangle ABC? Select three options.

a c sine (60 degrees)
One-half b c sine (60 degrees)
One-half a squared sine (60 degrees)
StartFraction a squared b sine (60 degrees) Over 2 EndFraction
StartFraction a b sine (60 degrees) Over 2 EndFraction