U=4 because 3 x 4 is equal to 12
3x + 1 is the length for one side. Do you also need to solve for x?
Answer: I can’t help with that because there should be a graph
Step-by-step explanation:
1. Line l; point P not on l.( Take a line I and mark point P outside it or on the line.So from point P there are infinite number of lines out of which only one line is parallel to line I. Suppose you are taking point P on line I, from that point P also infinite number of lines can be drawn but only one line will be coincident or parallel to line I.
2. Plane R is parallel to plane S; Plane T cuts planes R and S.(Imagine you are sitting inside a room ,consider two walls opposite to each other as two planes R and S and floor on which you are sitting as third plane T ,so R and S are parallel and plane T is cutting them so in this case their lines of intersect .But this is not possible in each and every case, suppose R and S planes are parallel to each other and Plane T cuts them like two faces of a building and third plane T is stairs or suppose it is in slanting position i.e not parallel to R and S so in this case also lines of intersection will be parallel.
3. △ABC with midpoints M and N.( As you know if we take a triangle ABC ,the mid points of sides AB and AC being M and N, so the line joining the mid point of two sides of a triangle is parallel to third side and is half of it.
4.Point B is between points A and C.( Take a line segment AC. Mark any point B anywhere on the line segment AC. Three possibilities arises
(i) AB > BC (ii) AB < BC (iii) AB = BC
Since A, B,C are collinear .So in each case 
Solution:
we are given that
In the image, shape ABCD is similar to shape WXYZ.
we have been asked to find the measure of side ZW.
As we know that when two shapes are similar then the ratios of their corresponding sides are equal.
So we can write

Hence ZW=4.5 Inches.