Ask your own question, for FREE!
Mathematics 9 Online
mikewwe13:

https://static.k12.com/nextgen_media/assets/8074848-NG_GMT_A_02_U01_Quiz_DP024_102_001_prompt.jpg Which lines are parallel in the square pyramid? Select each correct answer. A.​​​ BC←→ ​ and DE←→ B.​ AD←→ ​ and ​​ ​ BC←→ ​ C. AB←→ and AD←→ D. CD←→ and BE←→

mikewwe13:

@Vocaloid

bm717:

Parallel=lines that never intersect

mikewwe13:

the arrows is on the top

Vocaloid:

any ideas? for example, just test the answer choices one by one: are BC and DE parallel? check the original picture

mikewwe13:

yes

Vocaloid:

good, so A is one possibility what about choice B? are AD and BC parallel?

mikewwe13:

no

Vocaloid:

good, so eliminate B what about choice C? are AB and AD parallel?

mikewwe13:

no

Vocaloid:

good, what about choice D? are CD and BE parallel?

mikewwe13:

yes

Vocaloid:

good so A&D are your solutions

mikewwe13:

https://static.k12.com/nextgen_media/assets/1541442-IM1_141006_050213.jpg The figure shown is a rectangular prism. Which edges are parallel to AH¯¯¯¯¯¯ ? Select each correct answer. A. PA¯¯¯¯¯ B. BD¯¯¯¯¯ C. DK¯¯¯¯¯¯ D. BM¯¯¯¯¯¯ E. MK¯¯¯¯¯¯¯

mikewwe13:

the lines are on top

Vocaloid:

well let's try drawing them out |dw:1533917051213:dw|

Vocaloid:

|dw:1533917062876:dw| all the lines parallel to AH are marked in red - which choices correspond?

mikewwe13:

BD, PA, MK

Vocaloid:

hm not quite, PA is this side so it's not parallel|dw:1533917197978:dw| but BD + MK = your solutions

mikewwe13:

BD and MK are my only solutions

Vocaloid:

yup the others are perpendicular

mikewwe13:

https://static.k12.com/nextgen_media/assets/1541443-IM1_141006_050214.jpg The figure shown is a rectangular prism. Which edges are perpendicular to PR¯¯¯¯¯ ? Select each correct answer. A. QT¯¯¯¯¯ B. TJ¯¯¯¯¯ C. HP¯¯¯¯¯¯ D. TR¯¯¯¯¯ E. RA¯¯¯¯¯

Vocaloid:

similar logic as last time but we want all the perpendicular edges |dw:1533917381802:dw|

Vocaloid:

|dw:1533917387690:dw|

Vocaloid:

actually I missed one, include TR

mikewwe13:

QT, HP, TR

Vocaloid:

hm not quite, QT is parallel not perpendicular

Vocaloid:

notice how RA is also perpendicular to PR so it's every choice except QT

mikewwe13:

https://static.k12.com/nextgen_media/assets/1541446-IM1_141006_050217.jpg Rodrigo knows that AM←→−⊥MN←→− and UK←→⊥MN←→− . What other facts can Rodrigo conclude are true? Select each correct answer. A. AL←→∥UK←→ B. AL←→⊥LT←→ C. MN←→−∥LT←→ D. m∠MBK = 90°

mikewwe13:

1 attachment
mikewwe13:

by the way with the other question it's every choice but that doesn't include QT ?

Vocaloid:

yes

Vocaloid:

well let's go one by one AM is perp. to MN UK is perp. to MN there's a theorem that states: if two lines (let's call them A and B) are both perpendicular to the same line (let's call it C) then A + B are parallel making statement 1 true

Vocaloid:

however we don't know anything about LT (it "looks" perpendicular but there's no evidence such as angle measurements or markings to show that LT is parallel to anything) eliminating choices B +C

Vocaloid:

as for choice D: <MBK is the angle across from UBN, and UBN is 90 degrees so is <MBK also 90 degrees? remember the definition of vertical angles

mikewwe13:

it is

Vocaloid:

good so A+D are your solution

mikewwe13:

Vocaloid:

yikes let's go through them one by one look at lines AB + CD. they both are perpendicular to the same line, so using the logic from before are AB and CD parallel, perpendicular, or neither?

mikewwe13:

they look perpendicular

mikewwe13:

to me

Vocaloid:

|dw:1533918271489:dw|

Vocaloid:

|dw:1533918276763:dw|

Vocaloid:

notice how AB and BC are both perpendicular to GH which, by our earlier problem, means that AB and BC are ~parallel~ to each other

Vocaloid:

** AB and CD are parallel

mikewwe13:

ok

Vocaloid:

using the same logic, AB and EF are also parallel since they're perpendicular to the same line so so far we have the first two choices selected

mikewwe13:

AB and CD, and AB and EF are parallel

mikewwe13:

correct ?

Vocaloid:

good

Vocaloid:

now, let's look at IK and KL. they don't give us any angle information or any markings to show parallel and perpendicular so we can't determine anything about them

Vocaloid:

last one, CD and GH - take a look at the diagram and notice how there's a 90 degree angle between them - does that make them parallel or perpendicular?

mikewwe13:

perpendicular

Vocaloid:

awesome so the first two choices are parallel, the third choice is "cannot be determined" and the last choice is perpendicular ~

Vocaloid:

anyway I need to make lunch for my family, if you have any urgent questions you might be able to ask shadow if he can assist

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!