This question is solved applying the formula of the area of the rectangle, and finding it's width. To do this, we solve a quadratic equation, and we get that the cardboard has a width of 1.5 feet.
Area of a rectangle:
The area of rectangle of length l and width w is given by:

w(2w + 3) = 9
From this, we get that:

Solving a quadratic equation:
Given a second order polynomial expressed by the following equation:
.
This polynomial has roots
such that
, given by the following formulas:
In this question:


Thus a quadratic equation with 
Then


Width is a positive measure, thus, the width of the cardboard is of 1.5 feet.
Another similar problem can be found at brainly.com/question/16995958
Answer:
use the slope equation (y2-y1) / (x2 -x1). plug in values and solve
(-1 -7) / (9 -(-3)) (subtracting a negative is the same as adding a positive)
-8 / 12 (simplify)
m = -2/3
then, plug in one of the points and the slope into the slope-point equation.
(y - y1) = m (x - x1) (the point-slope form)
y - 7 = -2/3( x - (-3)) (plug in the slope and point 1 values, then solve)
y - 7 = -2/3x - 2 (add 7 to both sides)
y = 2/3x +5 (the answer)
Step-by-step explanation:
I hope this helps :))
To find the length of the diagonal, we need to calculate the length of the base first and then use the value to calculate the diagonal since we are given the value of height of the triangle.
<h3>Pythagorean Theorem</h3>
This theorem is used to find the missing side of a right angle triangle given that we have the length of two sides.
To calculate the base of the triangle, let's use Pythagorean theorem here

Having the length of the base, let's consider the height of the triangle which is 6 and substitute the values.

From the calculations above, the values of the triangle are
- diagonal = 7
- base = 3.61
- height = 6
Learn more on pythagorean theorem here;
brainly.com/question/231802
#SPJ1
They are circle and triangle.
Best of luck in geometry