What is the value of sin 10° · sin 50° + sin 50° · sin 250° + sin 250° · sin 10° equal to?

Correct option is B

sin 10° · sin 50° + sin 50° · sin 250° + sin 250° · sin 10°

sin 250° = - sin 70°

Step 1: Using the identity for sin(A) · sin(B)

We can apply the identity:

sin A · sin B = (1/2) [cos(A - B) - cos(A + B)]