Apply the law of cosines. and solve for A

A = 79.04239272, or 79
Answers:
1st pic:
a) 2
b) 2.5 or 2
2nd pic:
a) 4
b) 5
c) 9
3rd pic:
a) 5
b) 3
Note: I may not be correct on all of them. Some of them were confusing a little bit, so I just wanted to let you know. Please don't come after me in the comments if I am wrong with one of the answers. In reality, you should be doing this. Either way, I hope this helps! Please, please, PLEASE mark brainliest. I would really appreciate it. :)
Answer:
-10/3 is the answer
Step-by-step explanation:
Given are two complex numbers as

Recall Demoivre theorem as
(cosA+isinA)(cos A+isin B) = cos(A+B)+isin(A+B)
Hence here we have sum of angles as
A+B = 63+117 =180

=
Since sin180=0 and cos 180=-1
The water will last for 3 days
<em><u>Solution:</u></em>
Given that, village having a population of 4000, requires 150 litres of water per head per day
<em><u>Let us first find the volume of tank</u></em>
The tank measuring 20m x 15m x 6m
Length = 20 m
Breadth = 15 m
Height = 6 m


Thus volume of tank is 1800 cubic meter
From given,
Water required per person per day = 150 liters
<em><u>Therefore, water required for 4000 people per day is:</u></em>

Convert to meters

<em><u>How many days will the water of this tank last?</u></em>


Thus the water will last for 3 days
Answer:
80
Step-by-step explanation
Well every triangle has to equal 180 degrees.
So you would add the two degrees you already have, which on this one you would get 100.
Then, you would subtract that number from 180 to get 80.
Hope this helps you!!