The answer is C 102 degrees. It is so because a triangles 3 angles add up to 180 degrees. If you know 2 of your angles, you would add them together and subtract that by 180 to find your last angle.
Answer:
7.71 inches far from each edge of the wall you should place the shelf.
Step-by-step explanation:
Given:

Let,
AB = distance between the edges or distance of wall.
ED = size of the shelf.
C is the centre of the wall.
To Find:
Distance from the edge of the wall to the shelf, when the shell is placed at the center of the wall.
AE = DB = ?
Solution:
As we need to place the shelf exactly in the center.
First we will calculate the distance from the center of the wall to the edge.
So the distance from the centre of the wall to the edge will be exactly half of the size of the wall.

now the distance from the centre to the end of the shelf will be exactly half of the size of the shelf.

Now we want to calculate the distance from the edge of the wall to the shelf,that is the distance from the end of the shelf to the edge of the wall.

Therefore, 7.71 inches far from each edge of the wall you should place the shelf.
Answer:
use photo math it's great
Answer:
the system has no solutions
Step-by-step explanation:
the systems are shaded in different directions with no part of them intersecting
this means that there are no solutions