(1) See below for a diagram. Basically, the distance on the ground from the person to the building (34 ft) is adjacent to the angle of elevation (74 degrees) and the height of the building (labeled h in the diagram) is the side opposite the angle. Since we are dealing with opposite and adjacent we use the tangent of the angle and tan = opp/adj
Specifically, 


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 feet.
Please be sure your calculator is set to degrees (not radians) when you do this problem.
(2) Here since P & Q are complimentary it means that their sum is 90 degrees. Since this is a right triangle that means that the remaining angle (R) must be the right angle. See below for a diagram. 
sin = opp/hyp. As the sin Q =  9/41 this means that 9 is the length of the side opposite Q (the side PR) and 41 is the length of the hypotenuse. This makes the remaining side (QR) 40 in length.
cos = adj/hyp. If we focus on angle P the side adjacent (next to) is 9 and the hypotenuse is 41. Thus the cos of P = 9/41.
You could have also realized that if P & Q are complimentary the sin P = cos Q and the cos P = sin Q. We were not asked about tangent but it is also the case that tan P = cot Q and cot P = tan Q.
 
        
             
        
        
        
Answer:
   840 km
Step-by-step explanation:
The speed expression ...
   840 kilometers per hour
means the plane files 840 kilometers in each hour.
In 1 hour, it will travel 840 km.
 
        
             
        
        
        
Answer:
10n+10
Step-by-step explanation:
7n-7n+5n2+10
5n2+10
5n*2+10
10n+10
Hope this helps :D
#Team Rainbows
 
        
             
        
        
        
Answer:
The correct answer is 2x - y - 1 = 0
Step-by-step explanation:
To find this, use the ordered pair (1, 1) in any of the equations. If it results in a true statement then this can be an equation. 
2x - y - 1 = 0
2(1) - (1) - 1 = 0
2 - 1 - 1 = 0
0 = 0 (TRUE STATEMENT)