Anyone good at mathematics?

[HOGEPH]

How would I work out the 4 areas of a circle divided into 4 slices horizontally?

[Mattygooner]

HOGEPH said:

How would I work out the 4 areas of a circle divided into 4 slices horizontally?

Tell them they will get the piece of cake their bloody well given!

[JJCW]

Paint picture needed :P

[escargot]

Mattygooner said:

HOGEPH said:

How would I work out the 4 areas of a circle divided into 4 slices horizontally?

Tell them they will get the piece of cake their bloody well given!

[elster]

I know how to work out the areas.

But how do you mean sliced horizontally?

[Silent1]

[HOGEPH]

JJCW said:

Paint picture needed :P

A description will have to suffice.

Draw a circle

Draw a line on the diameter, dividing the circle in half horizontally.

In each of the semi-circles, draw a horizontal line, crossing the point at half the radius.

The area of the piece below the diameter is larger than the bottom slice, but how do I work out the two different areas?

[voyds9]

How accurate does it need to be. Would the area of the 4 approximate rhomboids be close enough.

[RichBurley]

elster said:

I know how to work out the areas.

But how do you mean sliced horizontally?

The OP means 3 evenly spaced lines.

[HOGEPH]

voyds9 said:

How accurate does it need to be. Would the area of the 4 approximate rhomboids be close enough.

Yes, for the purpose I need, but from a theory point, I guess there must be some sort of formula that is related to the radius and distance of the chord from the diameter.

[turbobloke]

General:

http://www.mathwords.com/a/area_segment_circle.htm

[HOGEPH]

turbobloke said:

General:

http://www.mathwords.com/a/area_segment_circle.htm

Thank you!

[dougc]

Google for a formula for calculating the area of a circle segment - I can't remember it off the top of my head.

Presuming that you know that all 4 area sectors are the same you'll only need to work out one.

ETA - Dammit too slow!

Edited by dougc on Friday 6th March 14:33

[bitwrx]

Basic principal is:

Work out area of segment.
Subtract the area of the triangular bit of the segment.

This gives you the area of the sector (the bit bounded by the perimeter and the chord [which is the horizontal line of which you speak]).

How you work out the area of the segment will depend on which numbers you already know. There are calculators out there to do it, but I'm having trouble finding a decent one at the mo.

I think I've understood you correctly. HTH.

ETA. Must type faster, but here's a calculator

Edited by bitwrx on Friday 6th March 14:39

[cheshire_cat]

bitwrx said:

Basic principal is:

Work out area of segment.
Subtract the area of the triangular bit of the segment.

This gives you the area of the sector (the bit bounded by the perimeter and the chord [which is the horizontal line of which you speak]).

How you work out the area of the segment will depend on which numbers you already know. There are calculators out there to do it, but I'm having trouble finding a decent one at the mo.

I think I've understood you correctly. HTH.

ETA. Must type faster, but here's a calculator

Edited by bitwrx on Friday 6th March 14:39

How does one work out the length of the chord?

[4hero]

Silent1 said:

[elster]

Would have asked for numbers, but it seems you have the formulae now.

[turbobloke]

cheshire_cat said:

How does one work out the length of the chord?

If you know the length of two sides (r) and the angle subtended at the centre by the chord, you could use the cosine rule.

[cheshire_cat]

turbobloke said:

cheshire_cat said:

How does one work out the length of the chord?

If you know the length of two sides (r) and the angle subtended at the centre by the chord, you could use the cosine rule.

But the point is, surely without drawing and measuring, you wouldn't?

[turbobloke]

cheshire_cat said:

turbobloke said:

cheshire_cat said:

How does one work out the length of the chord?

If you know the length of two sides (r) and the angle subtended at the centre by the chord, you could use the cosine rule.

But the point is, surely without drawing and measuring, you wouldn't?

Depends - on what the total information in the question is, or what the problem is trying to solve. That's why I said "if".