Review of Chapter 7

Okayy, so this week we reviewed for the trig test! So I am going to do my blog on a review of chapter 7. This is should be very easy because you should already know all of this. So lets get started! First, I am going to give you some formulas.

• K=1/2r^2 Ɵ
• K=1/2rs
• s=rƟ

In the last formula, r=distance between two objects, Ɵ=apparent size, and S=diameter of an object.

Okay, so now I am going to give you a few examples.

Example 1: A sector of a circle has a radius 8 cm and central angle 2 radians. Find its arc length and area.

In this problem,

• R(radius)=8cm
• Ɵ(central angle)=2
• K(area)=?
• S(arc length)=?

To solve this problem, you would use the equation k=1/2r^2Ɵ.

Therefore, k=1/2(8)^2(2) so k=64cm^2.

 

You then plug into k=1/2rs. Since you’re solving for s, it becomes k/1/2r=s.
Therefore s=64/4 so s=16cm.And those are your two answers!

 

Well, that's it for this weeeek. See ya later! Byeee.

 

--Halie!