The best way to multiply complicated problems mentally* is to break them into chunks.
Start with 20 times 8 to get 160, and then 8 times 5 to get 40. Add these together to get 200. 200 times 3 is 600, and 20 times 200 is 4000. Add these together to get your final answer, 4600.
In other words 8 x 20 + 8 x 5 = 200 200 x 3 + 200 x 20 = 4600
*I assumed you meant mentally, because otherwise you'd just multiply longhand, multiplying two of the three numbers and then multiplying their product with the third.
Answer:
Step-by-step explanation:
The area of an equilateral triangle with side length 
is equal to 
. Since the perimeter is 24 units and there are three equal sides to an equilateral triangle, each side is 
units.
Substituting in this value, we get:
Answer:
I think the answer is 0.3 in 0.4
Answer:
Step-by-step explanation:
