# Gcse maths question help I need to know the answer

Watch
Announcements
#1
I need help on a gcse question can you guys please help me 😀 topic - angle between a line and a plane

Here is the question and answer to part a I just can't work out part B 😞 sorry I know I worked part a in a dodgy way I can't explain it I know how to do it. But totally stuck on part bAttachment 344147Attachment 344149
0
5 years ago
#2
make a right angle triangle and use pythagoras theorem. Use the height you found in part a to make one side, the other side will be the half of a side of the cube so 30, and the last side is OE. so 30^2 + [answer to part a]^2 = OE^2

Go from there it's quite easy
0
5 years ago
#3
(Original post by Chittesh14)
I need help on a gcse question can you guys please help me ������ topic - angle between a line and a plane

Here is the question and answer to part a I just can't work out part B ������ sorry I know I worked part a in a dodgy way I can't explain it I know how to do it. But totally stuck on part bAttachment 344147Attachment 344149
greetings and salutations!

you should have found the height of the pyramid first - i'm unsure if you can imagine this, but you'll have to use half the diagonal of the square as a centre point (30 cm), from this point draw a line extending from the centre of the square to the top vertex - this is the unknown height. if you join this with the other side of the pyramid that is 50cm, you will get a right angled triangle. solve by pythagoras to find the height so:
let a be height, b and c the other sides: a^2 + b^2 = c^2
a^2 = (50)^2 - (30)^2 and then square root the answer which is 40.
add this to the height of the AE which is 60 so:
60 + 40 = 100 cm is the height of the vertex from the table.

i have some idea of how to do part b but i am unsure if it will be the correct answer ..
0
#4
greetings and salutations!

you should have found the height of the pyramid first - i'm unsure if you can imagine this, but you'll have to use half the diagonal of the square as a centre point (30 cm), from this point draw a line extending from the centre of the square to the top vertex - this is the unknown height. if you join this with the other side of the pyramid that is 50cm, you will get a right angled triangle. solve by pythagoras to find the height so:
let a be height, b and c the other sides: a^2 + b^2 = c^2
a^2 = (50)^2 - (30)^2 and then square root the answer which is 40.
add this to the height of the AE which is 60 so:
60 + 40 = 100 cm is the height of the vertex from the table.

i have some idea of how to do part b but i am unsure if it will be the correct answer ..
I have checked the answer in the book though and it says I am right lol 86.5 cm for part a.

Posted from TSR Mobile
0
#5
(Original post by AQASUX)
make a right angle triangle and use pythagoras theorem. Use the height you found in part a to make one side, the other side will be the half of a side of the cube so 30, and the last side is OE. so 30^2 + [answer to part a]^2 = OE^2

Go from there it's quite easy
The answer is 63.9 degrees but I don't know how to get there can u like work it out and show me the working out + answer please

Posted from TSR Mobile
0
X

new posts
Back
to top
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

### Poll

Join the discussion

#### Should there be a new university admissions system that ditches predicted grades?

No, I think predicted grades should still be used to make offers (627)
33.67%
Yes, I like the idea of applying to uni after I received my grades (PQA) (784)
42.11%
Yes, I like the idea of receiving offers only after I receive my grades (PQO) (368)
19.76%
I think there is a better option than the ones suggested (let us know in the thread!) (83)
4.46%