Question

Use trigonometric ratios to find the area of the triangle ABC

Answer 1

area=(1/2)a b sin(angle between side a and b)
it is simply (1/2)* base * height
if you choose side a as base you height become bsin (angle between side a and side b)

Answer 2

you can write (1/2) b c sinA=(1/2) a b sinC=(1/2)c a sinB