What is the range of this function please help

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.

7x+8y=-18, 4x-9y=-3 solve the system of equations

Triangle inequality theorem state if each set of three numbers can be the lengths of the sides of a triangle. 1. 9, 8, 22. 2. 5,10,12. 3. 7,10,22. 4. 4,11,12. 5. 11,9,10. 6. 10,4,19. 7. 3,12,10. 8. 4,3,2. 9. 6,5,13. 10. 7,12,20. me .