<h2>
Answer:</h2>
12
<h2>
Step-by-step explanation:</h2>
<u><em>The mean is also the average.</em></u>
Add up all the number of students all together:
12+13+14+9
48
Now, Divide the total amount of students (48) by the amount of numbers you added (in this case, 48/4 because we added 4 numbers wich are 12+13+14+9)
The average amount of students is 12
Theorem of cosine:
a²=b²+c²-2bc(cos α) ⇒cos α=-(a²-b²-c²) / 2bc
In this case:
a=15 cm
b=10 cm
c=5 cm
cos α=-(15²-10²-5²) / 2*10*5
cos α=-100 / 100
cos α=-1
A=arc cos -1=180º This is impossible, because:
A+B+C=180º; then B=C=0º This is impossible for make a triangle (B>0 and C>0 if we want to make a triangle).
Therefore: it is not possible can make a triangle with side lengths of 5 cm, 10 cm and 15 cm.
Answer:
check the picture
Step-by-step explanation:
I hope you get it
Answer:
900π
Step-by-step explanation:
surface area of a sphere: 4πr²
=> 4 × π × 15²
=> 900π
