Respuesta :

13. c
14. d
15. b
Sorry if I am not correct I'm only in 6th grade
9.[tex]V = \frac{\sqrt{3}}{2}a^{2}h[/tex]
   [tex]V = \frac{\sqrt{3}}{2}(4)^{2}(8)[/tex]
   [tex]V = \frac{\sqrt{3}}{2}(16)(8)[/tex]
   [tex]V = \frac{\sqrt{3}}{2}(128)[/tex]
   [tex]V = \frac{128\sqrt{3}}{2}[/tex]
   [tex]V = 64\sqrt{3}\ cm^{3}[/tex]
The answer is D.

10. V = ¹/₃πr²h
      V = ¹/₃(3.14)(6)²(10)
      V = ¹/₃(3.14)(36)(10)
      V = ¹/₃(3.14)(360)
      V = ¹/₃(1130.4)
      V = 376.8 cm³
The answer is C.

11. V = ¹/₃πr²h
      V = ¹/₃(3.14)(6)²(10)
      V = ¹/₃(3.14)(36)(10)
      V = ¹/₃(3.14)(360)
      V = ¹/₃(1130.4)
      V = 376.8 cm³
The answer is C.

12. V = 1
¹/₃πr³
      V = 1¹/₃(3.14)(3)³
      V = 1¹/₃(3.14)(27)
      V = 1¹/₃(84.78)
      V = 113.04 cm³
The answer is C.

13. V = 1¹/₃πr³
      V = 1¹/₃(3.14)(12)³
      V = 1¹/₃(3.14)(1728)
      V = 1¹/₃(5425.92)
      V = 7234.56 cm³
The answer is A.

14.        S = 4πr²
        324π = 4(3.14)(r)²
324(3.14) = 4(3.14r²)
   1017.36 = 12.56r²
     12.56      12.56
            81 = r²
              9 = r

V = 1¹/₃πr³
V = 1¹/₃(3.14)(9)³
V = 1¹/₃(3.14)(729)
V = 1¹/₃(2289.06)
V = 3052.08
The answer is D.

15. The answer is A.
16. The answer is A.
17. The answer is B.
18. The answer is C.