Just select the right one

Given: △abc, ab=15, bd=9 ad ⊥ bc , m∠c=30°. find: the perimeter of the triangle.

Avegetable garden and a surrounding path are shaped like a square together are 12 ft wide. the path is 1 feet wide. if one bag of gravel covers 8 square feet, how manu bags are needed to cover the path? round your answers to the nearest tenth.

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