tlg bantu yaa , 20 poin no 1 dan 2 ,

1) rusuk kubus = a cm
a) jarak E ke ABCD = jarak E ke A = EA = a cm (rusuk kubus)
b) jarak D ke DBFH = 1/2 . EG = 1/2 . a√2 = (a/2)√2 cm

2) a) volume Limas A.EFH
= 1/3 x AE x luas EFH
= 1/3 x a x (EF x EH)/2
= 1/3 x a x (a x a)/2
= 1/6 a^3 cm^3

b) ∆AFH = segitiga sama sisi karena AF = AH = FH = a√2 (diagonal sisi)
tinggi (t) = √((a√2)^2 - (a/2 √2)^2) = √(2a^2 - 2/4 a^2) = √(6/4 a^2)
= √((a^2/4) . 6) = a/2 √6
Luas AFH = 1/2 x alas x tinggi
= 1/2 . a√2 . a/2 √6
= 1/4 a^2 √12
= 1/4 a^2 .2√3
= 1/2 a^2 √3 cm^2