Which relationship in the triangle must be true? A
с
b
С
B
a
O sin(B) = sin(A)
O sin(B) = cos(90 - B)
cos(B) = sin(180 - B)
O cos(B) = cos(A)

Dexter read 11 science fiction books and 5 history books. lena read 9 science fiction books and 4 history books. compare the students’ ratios of science fiction books to history books. 1. determine the ratios’ form:    science fiction books to history books 2. write the ratios as fractions:    dexter: 115; lena: 94 3. rewrite with a common denominator. 4. compare. 5. answer the question. determine which shows the correct comparison of the ratios for this problem.