Answer: P=47 inches
Step-by-step explanation:
First, you have to find the other side lengths. Two of the sides are equal to 20 because this is a rectangle. The first blank would be 20 because 20 times the other side length is equal to 70. Then you would divide 70 by 20 which would equal x. x would equal 3.5 in. Then the perimeter would be:
2(20)+2(3.5)=P
P=47 inches
Draw a vector triangle. When you draw the horizontal and vertical components, you end up with a right triangle. The magnitude of the vector is equal to the hypotenuse of the triangle so you can use the Pythagorean theorem to calculate it. Rearrange the Pythagorean theorem to calculate the magnitude
Answer:
1078
Step-by-step explanation:
Total no of rows (n) = 22
Since, 18, 20, 22 ..... forms an arithmetic sequence with first term (a) = 18 and common difference (d) = 2.
We need to find: Total no of seats in the theatre 
Formula to be used:
![S_{n}= \frac{n}{2}\bigg[2a+(n-1)d\bigg]](https://tex.z-dn.net/?f=S_%7Bn%7D%3D%20%5Cfrac%7Bn%7D%7B2%7D%5Cbigg%5B2a%2B%28n-1%29d%5Cbigg%5D)
Plug the values of a, d and n in the above formula, we find:
![\implies S_{22}= \frac{22}{2}\bigg[2(28)+(22-1)(2)\bigg]](https://tex.z-dn.net/?f=%5Cimplies%20S_%7B22%7D%3D%20%5Cfrac%7B22%7D%7B2%7D%5Cbigg%5B2%2828%29%2B%2822-1%29%282%29%5Cbigg%5D)
![\implies S_{22}=11[56+(21)(2)]](https://tex.z-dn.net/?f=%5Cimplies%20S_%7B22%7D%3D11%5B56%2B%2821%29%282%29%5D)
![\implies S_{22}=11[56+42]](https://tex.z-dn.net/?f=%5Cimplies%20S_%7B22%7D%3D11%5B56%2B42%5D)
![\implies S_{22}=11[98]](https://tex.z-dn.net/?f=%5Cimplies%20S_%7B22%7D%3D11%5B98%5D)

Thus, there are total 1078 seats in the theatre.