Answer:
Step-by-step explanation:
AB^2 = HB^2 + AH^2 => AB = 15cm
Ta co cong thuc: 1/AH^2 = 1/AB^2 + 1/AC^2 => AC=20cm
Vay SABC= 1/2 .AB.AC = 1/2 .15.20=150cm^2
Answer: 285.2 kg
Step-by-step explanation:
Given
The volume of helium in the balloon is 
The density of the helium is 
Mass of the helium gas is given by the product of density and volume

Thus, the mass of gas is 285.2 kg