9514 1404 393
Answer:
434 -49π ≈ 280.1 cm²
Step-by-step explanation:
The shaded area is the difference between the enclosing rectangle area and the circle area.
The rectangle is 14 cm high and 31 cm wide, so has an area of ...
A = WH
A = (31 cm)(14 cm) = 434 cm²
The circle area is given by ...
A = πr²
A = π(7 cm)² = 49π cm²
__
The shaded area is the difference of these, so is ...
shaded area = rectangle - circle
= (434 - 49π) cm² ≈ 280.1 cm²
Drawing a diagram of a triangle may be helpful. The hypotenuse is irrelevant, but the vertical leg and the horizontal leg are useful. Since we know the engineer is looking up at a 45 degree angle from a distance of 200 feet, we can label the vertical leg the "opposite", since it is on the opposite side of the angle we are given. The horizontal leg then becomes the "adjacent". You can then use trigonometry to solve for the opposite.
The options are:
sin(theta)= opposite/hypotenuse
cos(theta)= adjacent/hypotenuse
tan(theta)= opposite/adjacent
Since we don't care about the hypotenuse, the last equation is the one to use. The angle we are given can be substituted in for theta:
tan(45)= x/200
1.61977519= x/200
x= 323.955038 feet
The second one is the right answer
