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 
Answer:
Is an experimental study
Step-by-step explanation:
In an observational study you don't control any aspect of the investigation you just observe the variables that you determined since the beginning without any intervention.
In this case you are controlling who sees one or the other video, then you are controlling one of the variables that is the type of video each group sees and because of this it is an experimental study. Researchers designed an experiment to prove the null hypothesis they had.
Answer:
because you can show the exact points an object is at
Step-by-step explanation:
For example: A car goes x many miles in y minutes. You can easily see how many miles the car goes in y minutes.
Hope this helps!
3x° is 60° , 2x° is 40° and 4x° is 80°
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How to determine the angles</h3>
Note that the sum of angles in a triangle is 180°
Solve for x in the triangle
Then,
3x° +2x° + 4x° = 180°
Add the x°
9x° = 180°
Divide both sides by 9
x° = 180÷ 9 = 20°
If x° = 20
Then 3x° = 3× 20 = 60°
2x° = 2 × 20 = 40°
4x°= 4× 20 = 80°
Therefore, 3x° is 60° , 2x° is 40° and 4x° is 80°
Learn more about angles in a triangle:
brainly.com/question/7620723
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