Maths trigonometry qs stuck

Take Your Pants Off

I cant seem to get qs. 8;10;12;14.
I tried so much and looked at youtube videod but none of them would relate to those qs.
Would much appreciate if someone could give me some direction.

Moody_mona

In q8, you'll need to use the area of a sector formula, but you need the radius. You can find the radius since you know the circumference (2*pi*r) is equal to 12pi.

I can't see q10 in that photo, I'll try again in a sec. Q12, think about what shape is formed. You don't have a formula for a shape like that so you need to work with what you know.

Q14, do you have the relevant formulae for this topic? You should be able to answer those fairly straightforwardly with the formulae in front of you.

Take Your Pants Off

Moody_mona wrote: »

In q8, you'll need to use the area of a sector formula, but you need the radius. You can find the radius since you know the circumference (2*pi*r) is equal to 12pi.

I can't see q10 in that photo, I'll try again in a sec. Q12, think about what shape is formed. You don't have a formula for a shape like that so you need to work with what you know.

Q14, do you have the relevant formulae for this topic? You should be able to answer those fairly straightforwardly with the formulae in front of you.

Thanks. Heres q19

Take Your Pants Off

And i still dont know how to do q8

Peregrine

Take Your Pants Off wrote: »

Thanks. Heres q19

That's not Q19..

Actually, I don't see a Q19 in that exercise at all. 2.1 in Text and Tests 4, right?

Edit: Just read that again, you mean 10, sorry.

Moody_mona

Take Your Pants Off wrote: »

And i still dont know how to do q8

You know the circumference. So let 2*pi*r = 12*pi and find r. Then use this in the area of a sector formula since you're given the area of it.

For q10, again think of the shape formed. You don't have a formula for that, so how can you use what you know to make that shape.

aunt aggie

Q8 asks you to set up the circumference of a full circle formula to equal 12pi and find the radius. Then you set up the area of a sector formula to equal 3pi. Now that we know the radius we can solve to find the unknown angle.

Are there any similar examples in your textbook?

Peregrine

Take Your Pants Off wrote: »

And i still dont know how to do q8

The area of a sector formula is [latex]area = \frac{r^2\theta}{2}[/latex]

You need to find the angle, you know the area and you kind of know the radius because they give you the circumference.

circumference [latex]= 2\pi r = 12\pi[/latex]
Solve for radius.

Use the area of a sector formula and solve for theta.

Take Your Pants Off

Thanks lads i got q.8

Take Your Pants Off

Any help in the others please.

aunt aggie

Now Q10 and 12 are fairly straight forward. Big shape minus little shape = Shaded Region. If you can do Q8 you dont need much help with those Good luck