What is the primary focus of the course section discussed in the introduction?

If the perimeter of a rectangle is 42 inches and the length is 3 inches longer than the width, what is the width?

In the rectangle perimeter problem, what is the length of the rectangle?

In a triangle, if the second angle is 30 degrees more than the first angle and the third angle is 8 times the first angle, what is the measure of the first angle?

Which of the following is a fact about the sum of angles in a triangle?

In the triangle angles problem, what is the measure of the third angle?

What is the perimeter of a rectangle if its area is 32 square inches and one side is twice the length of the other?

If the height of a triangle is 8 feet longer than its base and its area is 10 square feet, what is the base?

What is the circumference of a circle if its area is 9π?

In the triangle and circle area problems, what is the radius of the circle if its area is 9π?