Which three angles measure could be used to form a triangle?
@Vocaloid
hint - which choice has all three angles add up to exactly 180?
C
check your calculations again 55 + 70 + 105 does not equal 180 try the other choices
A
good
for a square pyramid surface area = area of the 4 triangular sides + the base the base is a square with side length 44, what's the area of the base?
1936
awesome so each other side is a triangle with base 44 and height 33, what's the area of each triangle? as a reminder area of triangle = (1/2)bh
726
good, and we have 4 of those so area of the four triangles = 4 * 726 so total area = 4 * 726 + 1936 = ?
4840
good so 4840 = your solution
since we have two adjacent angles on a straight line, the two angles add up to 180 which equation best represents this idea?
D
well done
sorry for the correction just had to fix the parentheses hm well, the radius of the cone is one half the radius of the cylinder so volume of cylinder/volume of cone = (pi * (2a)^2 * h)/(1/3 * pi * b^2 * h) where 2a is the radius of the cylinder and a is the radius of the cone simplify the expression. as a hint, h, pi, and a cancel out
ugh I keep messing this up, it should be a instead of b in the denominator
(pi * (2a)^2 * h)/(1/3 * pi * a^2 * h)
12/x
so meaning D 12
yup
well the brace is the hypotenuse of a right triangle with legs 8 and 15 right? so try applying the pythagorean theorem
D
check your calculations again, you cannot simply add the legs w/o squaring them first x^2 = 8^15 + 15^2 solve for x
15
*8^2 + 15^2
289
good, and if x^2 = 289 what is x?
17
C
good
start by distributing 9w(w-2) add 27 to both sides then factor or use the quadratic eqn
B
good
well the statement is that <3 and <7 are equal right? so the statement must be factually correct and provide a reason why <3 and <7 are congruent and corresponding angles based on the diagram that being said any ideas?
D
hm not quite supplementary angles are usually not congruent any thoughts on B or C?
B cause they are congruent
that's a good attempt but the key is "any two lines" vs "two parallel lines" the angles are only congruent if the transversal cuts thru two parallel lines therefore C is the factually correct statement that proves why <3 and <7 are congruent, and thus the best choice
if it's a straight line the points must be linear so we would want the choice where the x-values and the y-values both change at a constant rate
A B or D
if you had to choose one which would be your best choice? remember, x and y must change at a constant rate
B
well let's look at B x goes from 0 --> 4 --> 8 so it's increasing by 4 each time, so far so good y goes from -4 ---> 0 ---> 0 see how it increases by 4 but then doesn't increase from 0 to 0? that means choice B is not linear and thus not the solution any thoughts on A or D then?
D
good
we can set up a proportion where 1.5 inch/100 miles = 4.5 inch/x miles and solve for x
7
check your calculations again if you cross multiply the proportion you get 1.5 inch/100 miles = 4.5 inch/x miles 1.5x = 4.5*100 solve for x
0
1.5x = 4.5*100 x is being multiplied by 1.5 right? so divide both sides by 1.5 to solve for x.
300
good so 300 = your solution
|dw:1534217919570:dw|
we have another right triangle where legs are x and 28 and hypotenuse = 35 so x^2 + 28^2 = 35^2 solve for x (this is the first step)
21
good, now it wants the area of the rectangle which is just L*W so 21 * 28
588x
good so 588 = your solution
36.21
it just wants the area of the cone + the two spheres on top so area of a cone = (1/3)*pi*r^3*h area of sphere = (4/3)pi*r^3 let's start w/ the cone (1/3)*pi*r^2*h the diameter is 3 inch so the radius is 3/2 = 1.5 if r = 1.5 and h = 6 what's the area of the cone?
*made a typo, it should be r^2 not r^3 so you want to find (1/3)*pi*r^2*h
(1/3) * pi * (1.5)^2 * 6 = ?
14
good but let's keep it in terms of pi (1/3) * pi * (1.5)^2 * 6 = (1/3) * 2.25 * 6 pi = 4.5pi now let's move to the spheres (4/3)pi*r^3 = ? where r = 1.5
there was a problem and couldn't get back on, i wanted to answer but i had to refresh then it didn't act right so i tried again later
the site went down for a bit anyway (1/3) * pi * (1.5)^2 * 6 = 4.5pi then for the spheres simply calculate 2 * (4/3) * pi * (1.5)^3
28
good but let's leave it in terms of pi 2 * (4/3) * pi * (1.5)^3= 9pi so adding what we have so far 9pi + 4.5pi = 13.5 pi = your solution
well fact 1 says that a linear pair (two angles on a line) add up to 180 the linear pair is z + y fact 2 says that the exterior angle = the sum of the two remote interior angles that gives us z = w + x then you can substitute (w+x) into the first equation for z which choice best describes these steps?
B
please try to review what I have said the linear pair z + y = 180 the exterior angle z equals the sum of w and x please try to pick the choice that matches this idea
no hold on
A
good
|dw:1534252789869:dw| it's alittle hard to visualize but try imaginging a right triangle with MP as the hypotenuse
|dw:1534252865521:dw|
first step is to find this distance using the pythagorean theorem|dw:1534252894336:dw|
you have a right triangle with legs 4 and 5 find the hypotenuse
5.7
hm not quite let's let x = the hypotenuse then x^2 = 4^2 + 5^2 solve for x
you can leave it in radical form for now
sqr41
good then we want to find the length of MP by finding the hypotenuse of the bigger triangle|dw:1534253175325:dw|
we have a right triangle with legs sqrt(41) and 4, find the hypotenuse MP
41.49
hm not quite a^2 + b^2 = c^2 plug in the legs to get ( sqrt(41) ) ^2 + 4^2 = c^2 solve for c
sqr57
good however the answers are in decimals so we just plug that into a calculator to get about 7.5 which is your solution
anyway let's start a fresh question if possible, this one is already 100+ replies
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