The pythagorean theorem holds for every right triangle: given the legs 
and the hypothenuse 
, the triangle is right if and only if
So, you have to check:
So the first triangle can't be a right triangle.
So the second triangle is a right triangle.
The third triangle can't be right, because it has the same legs but a different hypothenuse
Finally, we have
So the last triangle can't be a right triangle.
Answer:
x=3
Step-by-step explanation:
I guessed and checked which x value would make ABC proportional to DBE. If x=3, than DB=8 which is double BE. If x=3, than AB=14 which is double BC. Since it is proportional, It should be correct. I don't remember the actual way you solve this with a formula but this makes sense to me.
12.15 km /h
Step-by-step explanation:
Step 1 :
Given
Distance between Airy Town to Brightvale = 9 km
Speed of Ricky = x km/h
Step 2:
Speed taken by Sam = x + y km/h
Time taken by Sam = 40 min = 40/60 hrs = 2/3 hrs
so we have (x+y) 2/3 = 9
Step 3:
Speed taken by Timothy = x - y km / h
Time taken by Timothy = 50 min = 50/60 = 5/6 hrs
= > (x-y) 5/6 = 9
Step 4 :
Solving the 2 equations
(x+y) 2/3 = 9 and (x-y) 5/6 = 9 we have
(2/3)x + 2/3(y) = 9 = > 2x + 2 y = 27
5/6(x) - 5/6(y) = 9 = > 5 x - 5 y = 54
Multiplying the first equation by 5 and the second by 2 we have ,
10 x + 10 y = 135 and 10 x - 10y = 108
Adding both,
20 x = 243 => x = 12.15.
This gives speed of Ricky as 12.15 km /h
Volume of pyramid:
A - base area
H - height
First count volume of one pyramid:
![V=\dfrac{1}{3} \cdot 3 \cdot 4=4 [\hbox{inch}^3]](https://tex.z-dn.net/?f=V%3D%5Cdfrac%7B1%7D%7B3%7D%20%5Ccdot%203%20%5Ccdot%204%3D4%20%5B%5Chbox%7Binch%7D%5E3%5D)
So by using 576 inch^3 you can make 576 : 4 =
144 pyramids
They would be perpendicular. hope this helps.
