Find the value of x that makes f(x) continuous

Atriangle has a side lengths of 18cm, 80 cm and 81cm. classify it as acute obtuse or right?

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.

Which of the following circles have their centers on the x-axis? check all that apply.