Relationship between the sines and cosines of complementary... Comple following. Part 1: Use a, b, and c to fill in the blanks. X 5 ? Make sure to use the appropriate upper-case or lower-case letters. sin A = COS A = sin B = COS B = Part 2: In A ABC, LA and LB are (Choose one) Part 3: Select all of the true statements. O sin A = cos B cos A = Cos B O sin A = sin B cos A = sin B None of the above is true. Part 4: Fill in the blank. sin (340) = cos