Can someone please solve this MATH??? This is very confusing and I need help

  see below

Step-by-step explanation:

These geometries seem to have to do mainly with chords.

In any circle, the perpendicular bisector of a chord passes through the center of the circle.

The relationship between chord length and distance from center can be found using the Pythagorean theorem on the right triangle formed by a radius to the end of the chord, the half-chord length, and the distance from center to chord midpoint. (This is why there are two conflicting answers in problem 3. TU should be given as 7.6, not 7.4.)

Considering the above, it should be no mystery that chords in a circle that are the same length are the same distance from center, and vice versa. When circles have the same radii (as circles C and D in problem 3), the same thing holds.

Any triangle formed by a chord and radii to its ends is (obviously) an isosceles triangle. For chords of the same length, all such triangles are (obviously) congruent.

a net is a diagram that shows a “flattened” view of a solid. in a net, each face and base is shown with all of its dimensions. a net can also serve as a pattern to build a three-dimensional solid.

a pyramid is a three-dimensional object with a base that is a polygon and triangular faces that meet at one vertex.

" the net of a triangular pyramid consists of four triangles. the base here we are given of the pyramid is a equilateral   triangle, and the lateral faces are also triangles "

step-by-step explanation:

let pq = qr = rs = x, and xz = y and zu = z.

if the horizontal lines are parallel, then corresponding segments are in proportion:

substitute:

therefore 3 = y = z.

xu = y + z → xu = 3 + 3 = 6