91.5 is the perimeter. It's just 5a.
Hmmm if the question is about the triangle and the "top" angle, the answer will be c= 140.
Answer:
Simplify
![Q-[R+S]-T](https://tex.z-dn.net/?f=Q-%5BR%2BS%5D-T)
The answer is:

Step-by-step explanation:
We have the expressions:

Now, we need simplify:
![Q-[R+S]-T](https://tex.z-dn.net/?f=Q-%5BR%2BS%5D-T)
We need to replace each term by the expressions:
![7m+3n-[(11-2m)+(n+5)]-(-m-3n+8)](https://tex.z-dn.net/?f=7m%2B3n-%5B%2811-2m%29%2B%28n%2B5%29%5D-%28-m-3n%2B8%29)
We need to remember the rule of signs:



With this in mind we solve the parentheses:
![7m+3n-[(11-2m)+(n+5)]-(-m-3n+8)](https://tex.z-dn.net/?f=7m%2B3n-%5B%2811-2m%29%2B%28n%2B5%29%5D-%28-m-3n%2B8%29)
![7m+3n-[11-2m+n+5]+m+3n-8](https://tex.z-dn.net/?f=7m%2B3n-%5B11-2m%2Bn%2B5%5D%2Bm%2B3n-8)

let's group common terms

We must add and subtract common terms:

The answer is:

No. 1/4 of an hour is 15 minutes..
15 minutes read every day for 15 days is 225 minutes, which is less than 500
Answer:
141.37 cm
Step-by-step explanation:
If we're going off of the blue shaded region, the area of the full circle is 254.47 cm^2. Then we calculate the area of the inner circle. This gives you 113.1. Now you must subtract the area of the inner circle by the area of the outer circle. 254.47-113.1. This gives you 141.37, which should be your answer.