Answer:
B
Step-by-step explanation:
sames sides same angle
180=90+2x
180-90=2x
90=2x
x=45
S=22.17
Step-by-step explanation:
v/r=u/s
18/19=21/s
18s=21(19)
18s=399
18s/18=399/18
s=22.17
Answer: y = 3x + 7
Step-by-step explanation:
Since we are given the slope and y intercept we could write the equation in slope intercept form as y=mx +b .Only m and b are needed to write the equation.M is the slope and B is the y intercept.
Answer:
V = 120.6796
LA = 110.8513
SA = 174.8513
Step-by-step explanation:
Let me know if you need more of an explanation for any of these
First we need the height, one way to find that out is to use the diagonal of the and one of the diagonal edges of the pyramid. Specifically we will need half of the diagonal of the square. We will call the diagonal of the square d.

Gonna leave it like that for ease of writing. So then half of the diagonal is 
The height, h, will be
. Plugging everything in gets us 
last, we need to find slant height, which we will call s.

s is also the height of the triangles for purposes of finding area. Now for the volume and areas.
Volume is area of the base times height divided by 3, so 
Lateral area is the sum of the four areas of the triangles, and each of those are
so the whole lateral area is 4 times that. So we get 
Total surface area is the lateral surface area + the area of the base, so 110.8513 + 64 = 174.8513
I actually posted this a while ago and it got answerd by a smart person so here's what I understood
the error is that it assumes that √(x²)=x
because if x is negative, it becomes positive
that's how the 2nd line is wrong
the 2nd line is the first wrong step
it goes from 4-9/2+9/2
so it goes from 4-4.5+4.5
notice the part under the parenthsees
√((4-4.5)²)
if we evaluate 4-4.5, we get -0.5
but by squaring it we get 0.5
-0.5+4.5=4, yes
but when we square it we get
0.5+4.5=5, that is how it works