Write an equation of the line below

The ratio of the measures of the three angles in a triangle is 2: 9: 4. find the measures of the angels

Which of the expressions (on the photo document i inserted) together represent all solutions to the following equation? 8cos(12x)+4=-4 *the answer should be in degrees.* > i would like for someone to explain the process to find the solutions for this.

Atemperature of 1.64◦f corresponds to answer in units of ◦c.