check the picture below.
so, when we have a line from a 90° angle running perpendicular to the opposite side, like in this case, we end up with three similar triangles, a large one containing the other two, a medium and a small one.
now, using the sides proportions as you see there, of the small and large one, we get that much.
Mean: [45+65+30+50+20+30]/6 = 40.2
Median
First order the number {20, 30, 30,45, 50, 50}
The median is the average of the two values in the middle of the list: (30+45)/2 = 37.5
Mode: 30 and 50 (they are repeated the same number of times)
We want to use elimination to solve
y = 0 (1)
x + y = 40 (2)
Multiply (1) by -1 to eliminate y.
-y = 0 (3)
Add (2) and (3).
x + y + (-y) = 40 + 0
x = 40
Answer: Multiply by -1.

The sign at the end changes because both sides of the equation are being divided by a negative number.
Answers:
The area for the square on the left is 81m^2. This is found because all sides of this square are the same, so the length and width are the same. Just multiply 9 x 9.
The area for the triangle is 31.5m^2. We find the left side is 9 meters because the triangle shares the same side as the square on the left side. We also find the bottom side is 7 because that is the length of each side of that square because all sides on a square is the same. We then multiply 9 times 7, getting 63, we divide this by 2 because it’s a triangle.
The square on the right has the area of 225 because both length and width is 15.