Complementary angles sum to 90°. Supplementary angles sum to 180°.
Answer:
13.5 answer is 13.5 and one cost 4.5
<h2>
Explanation:</h2>
In every rectangle, the two diagonals have the same length. If a quadrilateral's diagonals have the same length, that doesn't mean it has to be a rectangle, but if a parallelogram's diagonals have the same length, then it's definitely a rectangle.
So first of all, let's prove this is a parallelogram. The basic definition of a parallelogram is that it is a quadrilateral where both pairs of opposite sides are parallel.
So let's name the vertices as:

First pair of opposite sides:
<u>Slope:</u>

Second pair of opposite sides:
<u>Slope:</u>

So in fact this is a parallelogram. The other thing we need to prove is that the diagonals measure the same. Using distance formula:

So the diagonals measure the same, therefore this is a rectangle.
-7x - 2y = 19
4x + y = -12
Set y equal to each other (opposite signs are fine and you could also set x equal instead of y)
-7x - 2y = 19
8x + 2y = -76
Add equations together
x = -52
Plug x value into an equation
4(-52) + y = -12
Solve for y
-208 + y = -12
y = 196
Hope this helps! ;)
D.
Step-by-step explanation:
because cos0 = b/h
so cos0 = 8/15