2c – d at c = 6, d = –3

In triangle abc, the length of side ab is 12 cm, the length of side bc is 5 cm, and the length of side ca is 9 cm. find the measure of angle a using the law of cosines.

Which of these angles are complementary? a. 45o and 45o b. 63o and 117o c. 45o and 135o d. 90o and 45o

Quadrilateral abcd is a parallelogram with diagonals that intersect at point e. which of the following statements is true?