Two chords of a circle, and , intersect at a point . is twice as long as , , and .

Give the length of .

Two chords of a circle, and , intersect at a point . is 12 units longer than , , and .

Give the length of (nearest tenth, if applicable)

A diameter of a circle is perpendicular to a chord at point . and . Give the length of (nearest tenth, if applicable).

A diameter of a circle is perpendicular to a chord at a point .

What is the diameter of the circle?

Two chords of a circle, and , intersect at a point .

Give the length of .

Figure is not drawn to scale

In the provided diagram, the ratio of the length of to that of is 7 to 2. Evaluate the measure of .