Oh sorry , I meant that. But how will I use the formula if I don't know the theta, like it's embedded in the formula , and if I use the formula, I will be left with the theta and I won't be able to get my radiusYou don't need to know the angle. Did you see my post #3?
(You have marked the angle alpha \(\displaystyle \alpha\). I think your "Fitta" is meant to be "theta" \(\displaystyle \theta\).)
OK, I am going to have a look and try to get it ,As I said in Post #3:
The total perimeter of the minor sector + the total perimeter of major sector = circumference + 4r
Can you see why?
(You don't have to work out the total perimeter of each sector separately, so you don't need he angle)
Umm , sorry but I can't understand why this formula, like the logic behind it.The total perimeter of the minor sector + the total primeter of major sector
= circumference + 4r
Can you see why?
And also I can't apply it to the question , how are u gonna do that. ???Umm , sorry but I can't understand why this formula, like the logic behind it.
OK I'll step you through it. Firstly draw the two shapes (sectors) separately that you have to find the total perimeter of.Umm , sorry but I can't understand why this formula, like the logic behind it.
A sector is the region bounded by an archive and two radii of the circleI know that. Please answer my questions. I am trying to help you understand.
Do you know what a sector is?
Have you drawn the two sectors separately?
Do you know what the perimeter of a sector is? (Not the value, the concept)
Ok good. Now look at your two sectors. The total combined perimeters is made up of 4 radii and a full circle. Can you see that?The perimeteris of the two sectorhas alreadybeen given ,
A sector is the region bounded by an archive and two radii of the circle
The perimeter of a sector is the length of arc + the 2 radius
And I have drawn the two sector separately
YesI
Ok good. Now look at your two sectors. The total combined perimeters is made up of 4 radii and a full circle. Can you see that?
Equal the given perimeter to the formula to get the radius, isn't it?OK so the combined perimeters are equal to \(\displaystyle 4r+2\pi r = (4 +2\pi)r\).
You also know that the combined perimeter is 123.40cm.
So now what?