Hi there! The answer is C.
The area of the square in the middle is the following:

Hence, the area of the square is 25 cm^2.
The area of one triangle is the following:

Hence, the total area of the four triangles is 4 × 20 = 80 cm^2.
Therefore, the total area of the pyramid is 80 + 25 = 105 cm^2. The answer is C.
Answer:
3
Step-by-step explanation:
If your talking about the x where it says 3x in, then
3x = 9
x = 3
Answer: 6.7*10^-5
Step-by-step explanation:
Answer:
Step-by-step explanation:
- DC = AC = x is the radius
<u>Using the Pythagorean theorem, find x:</u>
- (x + 9)² - x² = 15²
- x² + 18x + 81 - x² = 225
- 18x = 225 - 81
- 18x = 144
- x = 144/18
- x = 8