The area of a circle is pi * r^2
The radius of the circle is 6
So the area of the full circle is pi*36
1/4 of the circle is cut off so we have to take a fourth off the area.
36pi * 3 / 4 = 27pi
Or 84.823 cm^2
Answer:

Step-by-step explanation:
we have:
7a^2+4a+8 -5a^2 -4a -4
2a^2 +4
Answer:
422.44 feet
Step-by-step explanation:
Let A, B, X, and H represent the left-most observation point, the observation point to its right, the point immediately below the apex, and the height of the apex, respectively.
Then the definition of the cotangent function tells us ...
AX = H·cot(42°)
BX = H·cot(48.85°)
Since the figure tells us AB = 100 feet, we have ...
AB = AX -BX
100 = H·cot(42°) -H·cot(48.85°)
H = 100/(cot(42°) - cot(48.85°)) ≈ 422.44 . . . . ft
The current height of the pyramid is 422.44 feet.
Discount amount: $160.20
Sale price: $729.80