First, we have to find the length of each side of triangle. Equilateral triangle means 3 sides r in same length, so each side will be 21 ÷ 3 = 7
Now we need to calculate the height of the triangle. We can do this by Pythagoras theorem
Let the height be h
(7/2)^2 + x^2 = 7^2
The area should be 6.0621778265
Or u can say 6.06 corrected to 3 sig fig
Ok what do u need help with?
1 foot = 12 inches. If you multiply 12 by 12 and then add 5, you get 149. 149 is less than 162 so it will be able to fit!
This problem can be represented through the following equation
A = A₀(1/2)^t/h
where
A-----------> is the amount of substance left after time t
A₀ ----------> is the original amount---------> 2 g
h-------------> is the half-life-----------> 8 days
for A=0.04 g
t=?
0.04 = 2(1/2)^t/8
0.02 = (1/2)^t/8
Take ln on both sides:
ln(0.02) = ln [(1/2)^t/8]
ln(0.02) = (t/8)(ln 1/2)
t = 8*ln(0.02)/ln(1/2)
t = 45.15 days
the answer is 45.15 days
