Use a calculator to show that each of the following pairs of coterminal angles \( \theta \) and \( \beta \) have the same values, correct to four decimals, for the sine ratio.
a. \( \theta = 100 ^ { \circ } , \beta = 460 ^ { \circ } \) b. \( \theta = 245 ^ { \circ } , \beta = - 115 ^ { \circ } \)
c. \( \theta = - 75 ^ { \circ } , \beta = - 1155 ^ { \circ } \) d. \( \theta = 2000 ^ { \circ } , \beta = 920 ^ { \circ }\)