Answer:
The lateral area is equal to

Step-by-step explanation:
In this problem the lateral area is equal to the area of one equilateral triangle multiplied by 
To find the area of one equilateral triangle calculate the height
The area of the triangle is equal to

we have

Applying the Pythagoras theorem

The area of one triangle is equal to

so
The lateral area is equal to

Correct answer is: distance from D to AB is 6cm
Solution:-
Let us assume E is the altitude drawn from D to AB.
Given that m∠ACB=120° and ABC is isosceles which means
m∠ABC=m∠BAC = 
And AC= BC
Let AC=BC=x
Then from ΔACD , cos(∠ACD) = 
Since DCB is a straight line m∠ACD+m∠ACB =180
m∠ACD = 180-m∠ACB = 60
Hence 

Now let us consider ΔBDE, sin(∠DBE) = 

Answer:
Under 99% confidence level we can say that mean speed of the new chips is greater than that of the old chips
Step-by-step explanation:
: Mean speed of the new chip is the same as the old chip
: Mean speed of the new chip is greater than the old chip
to calculate the z-statistic we can use the formula:
z=
if we put the numbers then
z=
=4.8171
The probability of this z-statistic is < 0.001 Therefore Under 99% confidence level we can say that mean speed of the new chips is greater than that of the old chips
-4 = 8m + 18n
-18n = 8m + 4
/-18 /-18 /-18
n = 8m/-18 + 4/-18
I'm not sure so yeah