[問題]GWD 07-22

[suncake]

What is the volume of the cube above?
(1) The surface area of the cube is 600 square inches.
(2) The length of diagonal AB is 10 inches.


Ans: D

答案為什麼是D呢？
(1)跟(2)合併要如何算啊？

謝謝

[twkevin]

What is the volume of the cube above?
(1) The surface area of the cube is 600 square inches.
(2) The length of diagonal AB is 10 inches.


Ans: D

答案為什麼是D呢？
(1)跟(2)合併要如何算啊？

謝謝

cube是正立方體, 設邊長a
(1) 總表面積=600 = 6*a^2, a=10, volume=10^3=1000
(2) 設B的下面那點C
AC=跟號2*a ; AB^2=AC^2+BC^2=2a^2+a^2=3a^2=(10跟號3)^2
a=10, v=1000

你題目漏了10跟號3

[suncake]

喔喔 我了解了

謝謝你