Ask your own question, for FREE!
Mathematics 19 Online
mikewwe13:

Which three angles measure could be used to form a triangle?

mikewwe13:

@Vocaloid

mikewwe13:

1 attachment
Vocaloid:

hint - which choice has all three angles add up to exactly 180?

mikewwe13:

C

Vocaloid:

check your calculations again 55 + 70 + 105 does not equal 180 try the other choices

mikewwe13:

A

Vocaloid:

good

mikewwe13:

1 attachment
Vocaloid:

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?

mikewwe13:

1936

Vocaloid:

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

mikewwe13:

726

Vocaloid:

good, and we have 4 of those so area of the four triangles = 4 * 726 so total area = 4 * 726 + 1936 = ?

mikewwe13:

4840

Vocaloid:

good so 4840 = your solution

mikewwe13:

1 attachment
Vocaloid:

since we have two adjacent angles on a straight line, the two angles add up to 180 which equation best represents this idea?

mikewwe13:

D

Vocaloid:

well done

mikewwe13:

1 attachment
Vocaloid:

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

Vocaloid:

ugh I keep messing this up, it should be a instead of b in the denominator

Vocaloid:

(pi * (2a)^2 * h)/(1/3 * pi * a^2 * h)

mikewwe13:

12/x

mikewwe13:

so meaning D 12

Vocaloid:

yup

mikewwe13:

1 attachment
Vocaloid:

well the brace is the hypotenuse of a right triangle with legs 8 and 15 right? so try applying the pythagorean theorem

mikewwe13:

D

Vocaloid:

check your calculations again, you cannot simply add the legs w/o squaring them first x^2 = 8^15 + 15^2 solve for x

mikewwe13:

15

Vocaloid:

*8^2 + 15^2

mikewwe13:

289

Vocaloid:

good, and if x^2 = 289 what is x?

mikewwe13:

17

mikewwe13:

C

Vocaloid:

good

mikewwe13:

1 attachment
Vocaloid:

start by distributing 9w(w-2) add 27 to both sides then factor or use the quadratic eqn

mikewwe13:

B

Vocaloid:

good

mikewwe13:

1 attachment
Vocaloid:

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?

mikewwe13:

D

Vocaloid:

hm not quite supplementary angles are usually not congruent any thoughts on B or C?

mikewwe13:

B cause they are congruent

Vocaloid:

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

mikewwe13:

1 attachment
Vocaloid:

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

mikewwe13:

A B or D

Vocaloid:

if you had to choose one which would be your best choice? remember, x and y must change at a constant rate

mikewwe13:

B

Vocaloid:

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?

mikewwe13:

D

Vocaloid:

good

mikewwe13:

1 attachment
Vocaloid:

we can set up a proportion where 1.5 inch/100 miles = 4.5 inch/x miles and solve for x

mikewwe13:

7

Vocaloid:

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

mikewwe13:

0

Vocaloid:

1.5x = 4.5*100 x is being multiplied by 1.5 right? so divide both sides by 1.5 to solve for x.

mikewwe13:

300

Vocaloid:

good so 300 = your solution

mikewwe13:

1 attachment
Vocaloid:

|dw:1534217919570:dw|

Vocaloid:

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)

mikewwe13:

21

Vocaloid:

good, now it wants the area of the rectangle which is just L*W so 21 * 28

mikewwe13:

588x

Vocaloid:

good so 588 = your solution

mikewwe13:

1 attachment
mikewwe13:

36.21

Vocaloid:

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?

Vocaloid:

*made a typo, it should be r^2 not r^3 so you want to find (1/3)*pi*r^2*h

Vocaloid:

(1/3) * pi * (1.5)^2 * 6 = ?

mikewwe13:

14

Vocaloid:

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

mikewwe13:

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

Vocaloid:

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

mikewwe13:

28

Vocaloid:

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

mikewwe13:

1 attachment
Vocaloid:

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?

mikewwe13:

B

Vocaloid:

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

mikewwe13:

no hold on

mikewwe13:

A

Vocaloid:

good

mikewwe13:

1 attachment
Vocaloid:

|dw:1534252789869:dw| it's alittle hard to visualize but try imaginging a right triangle with MP as the hypotenuse

Vocaloid:

|dw:1534252865521:dw|

Vocaloid:

first step is to find this distance using the pythagorean theorem|dw:1534252894336:dw|

Vocaloid:

you have a right triangle with legs 4 and 5 find the hypotenuse

mikewwe13:

5.7

Vocaloid:

hm not quite let's let x = the hypotenuse then x^2 = 4^2 + 5^2 solve for x

Vocaloid:

you can leave it in radical form for now

mikewwe13:

sqr41

Vocaloid:

good then we want to find the length of MP by finding the hypotenuse of the bigger triangle|dw:1534253175325:dw|

Vocaloid:

we have a right triangle with legs sqrt(41) and 4, find the hypotenuse MP

mikewwe13:

41.49

Vocaloid:

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

mikewwe13:

sqr57

Vocaloid:

good however the answers are in decimals so we just plug that into a calculator to get about 7.5 which is your solution

Vocaloid:

anyway let's start a fresh question if possible, this one is already 100+ replies

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!