I cant really see your pic
Answer:
Step-by-step explanation:
<h3>To prove quadrilateral is a square:</h3>
a) Slope of CB
C(-3,-1) ; B = (0,3)

![\sf = \dfrac{3-[-1]}{0-[-3]}\\\\ =\dfrac{3+1}{0+3}\\\\ = \dfrac{4}{3}](https://tex.z-dn.net/?f=%5Csf%20%3D%20%5Cdfrac%7B3-%5B-1%5D%7D%7B0-%5B-3%5D%7D%5C%5C%5C%5C%20%3D%5Cdfrac%7B3%2B1%7D%7B0%2B3%7D%5C%5C%5C%5C%20%3D%20%5Cdfrac%7B4%7D%7B3%7D)

b) D(1,-4) ; A(4,0)
![Slope \ of \ DA = \dfrac{0-[-4]}{4-1}\\](https://tex.z-dn.net/?f=Slope%20%5C%20of%20%5C%20DA%20%3D%20%5Cdfrac%7B0-%5B-4%5D%7D%7B4-1%7D%5C%5C)


Slope of CB = slope of DA
c) C(-3,-1) ; D(1 , -4)
![\sf Slope \ of \ CD =\dfrac{-4-[-1]}{1-[-3]}](https://tex.z-dn.net/?f=%5Csf%20Slope%20%5C%20of%20%5C%20CD%20%3D%5Cdfrac%7B-4-%5B-1%5D%7D%7B1-%5B-3%5D%7D)


So, CD is perpendicular to CB
d) B(0,3) ; D(1,-4)

e) C(-3,-1) ; A(4,0)
![\sf Slope \ of \ CA = \dfrac{0-[-1]}{4-[-3]}\\](https://tex.z-dn.net/?f=%5Csf%20Slope%20%5C%20of%20%5C%20CA%20%3D%20%5Cdfrac%7B0-%5B-1%5D%7D%7B4-%5B-3%5D%7D%5C%5C)


So, CA is perpendicular to BD

Answer:
if im understanding right, answer is 207
Step-by-step explanation:
1000 + 1000 = 2000
7 x 10 = 70
2070 / 10 = 207
82*100/40 = 205
<span>40% 0f 205 = 205*40% = 205*40/100 = 82
hopes this helps :) :D :)</span>
Cuz it can help you later on in the fuchure