Step-by-step explanation:
AAS can be used prove that △ABC ≅ △DEF
Given:
circular pool with a diameter of 25 meters.
find: area of the bottom of the pool.
It is safe to assume that the diameter of the pool is the same from the top of the pool to the bottom of the pool.
Area of a circle = π r²
where:
π = 3.14
r = diameter / 2 = 25 meters / 2= 12.5 meters
Area of a circle = 3.14 * (12.5m)²
= 3.14 * 156.25 m²
Area of a circle = 490.625 m²
490.625 m² round to the nearest tenth is 490.60 m²
We round down because the number after 6 is 2. Whenever a number to be rounded off is followed by 0,1,2,3,and 4. Then, the number is rounded down.
First, let me do the Mathematical part of that, and then I shall explain the theory behind it.
Mathematical part:
We are going to multiply 513 with 46. So the two partial products that we are going to choose are 40 and 6.
Multiply 513 with 6 first.
513
x46
--------------------------
18 (as 6*3 = 18)
60 (as 6*10 = 60; In 513, the digit at tenths place is 1, so 1*10=10)
3000 (as 6*500 = 3000; In 513, 5 is at hundredth place, so 5*100=500)
120 (as 40*3 = 120; since 4 is at the tenth place, so 4*10=40)
400 (as 40*10 = 400)
20000 (as 40*500 = 20000)
--------------------------
23598 (Add all of them)
Theory:
As you can see above that we have chosen the two partial products individually which are 6 and 40. Since 4 in 46 is in tenth place, we have to consider it 40 (since 4*10 = 40). One by one, we first multiply 6 with 513. Then we move to the tenth place, and multiply 513 with 40. At the end, we have added all the results we found after multiplication.
Check: If we check the multiplication result by using the calculator, we would get the same result (23598).
Another Method (instant):
513 * (40+6) = (513*40) + (513*6) = 23598.
10(4^2-(9)
Since 16-9 is 7
And 10 times 7 is 70
