# How do I work out the perimeter?

Watch
Announcements
#1
Hi, basically I’m really confused on how to work out this question. I’ve tried, but tbh I’m not sure where to start. Any help would be appreciated
Last edited by #anonymous_user; 1 month ago
0
1 month ago
#2
(Original post by #anonymous_user)
Hi, basically I’m really confused on how to work out this question. I’ve tried, but tbh I’m not sure where to start. Any help would be appreciated
What is the question?
0
1 month ago
#3
(Original post by L-K)
What is the question?
lmao

'Hey I don't know what this picture is
Does anybody else? '
*Attaches no picture*
0
#4
(Original post by L-K)
What is the question?
Ooops I’m so sorry lol, didn’t realise it wasn’t attached. Let me try again
0
1 month ago
#5
(Original post by #anonymous_user)
Hi, basically I’m really confused on how to work out this question. I’ve tried, but tbh I’m not sure where to start. Any help would be appreciated
Well, what's the length BF? And if FBC is a quarter circle, what length does CF have to be?
0
#6
(Original post by davros)
Well, what's the length BF? And if FBC is a quarter circle, what length does CF have to be?
I know that BF = 9, but I’m not completely sure on CF. I was guessing that would be 9 too, but idk? 😬
0
1 month ago
#7
(Original post by #anonymous_user)
I know that BF = 9, but I’m not completely sure on CF. I was guessing that would be 9 too, but idk? 😬
Well BF and CF are both radii (radius’) of the circle, so it’s makes sense that they are te same value
Can you work out the length B to C?
What about the triangle length C to D and the perimeter of the rectangle BAED
1
1 month ago
#8
(Original post by #anonymous_user)
I know that BF = 9, but I’m not completely sure on CF. I was guessing that would be 9 too, but idk? 😬
Correct. You have a quarter circle and angle BFC is 90 degrees, so BF and CF are radii. You can use this to get the perimeter of the quarter circle.

You can subtract FC from 41 to get the unknown length of the rectangle at the bottom, which gives you 2 other parts of the perimeter

Finally you need the hypotenuse of the right-angled triangle, so you should be good to go
1
#9
(Original post by davros)
Correct. You have a quarter circle and angle BFC is 90 degrees, so BF and CF are radii. You can use this to get the perimeter of the quarter circle.

You can subtract FC from 41 to get the unknown length of the rectangle at the bottom, which gives you 2 other parts of the perimeter

Finally you need the hypotenuse of the right-angled triangle, so you should be good to go
Ahh okay, thank you so much for your help!!
0
#10
(Original post by laurawatt)
Well BF and CF are both radii (radius’) of the circle, so it’s makes sense that they are te same value
Can you work out the length B to C?
What about the triangle length C to D and the perimeter of the rectangle BAED
Would BC be (pi x 18) divided by 4, and to find CD, I could just use Pythagoras?
0
1 month ago
#11
(Original post by #anonymous_user)
Would BC be (pi x 18) divided by 4, and to find CD, I could just use Pythagoras?
Sorry for the delay in getting back to you - yes to both of your questions!
0
#12
(Original post by laurawatt)
Sorry for the delay in getting back to you - yes to both of your questions!
No worries, thanks so much for your help and have a good day!
1
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

#### Do you have the space and resources you need to succeed in home learning?

Yes I have everything I need (250)
57.34%
I don't have everything I need (186)
42.66%

View All
Latest
My Feed

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

Why not re-start the conversation?

### 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.