By tracing the edges, we can calculate that the perimeter of figure 1 is 4 units, and the perimeter of figure 2 is 12 units. What is the perimeter of figure 3?
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We can set up a function to calculate the perimeter. Let the figure no. be x , then ---->
f ( x ) = 4 + 8 ( x − 1 ) where f ( x ) = Perimeter of Figure x .
Nice logic ;-)
Nice! I did it the same way :-)
Whaaaaaaaaaaaaaaaaaaaaaaaat
i just knew that it has the same perimeter as a square of the same size.
It actually helps on what you are doing
It's hard but it's helps
Excellent solution. We should say that when a box is added to one of the four ends, it adds exactly 2 units, (not edges).
Number of boxes 'n' P=2n+2
This formula feels so quick! :-D
Your solution is the best. You use explicit formula. How did you come to this solution?
We can simply count the each side of a square which faces the outer side, and find 20 of them:
well if they wrote it "by counting sides of each square..." Instead of "by counting edges"...
Focus on the ratio here. For one square the perimeter was 4. For another 4 squares the perimeter raised to 12. So, the perimeter raises 8 units for 4 square. So, the perimeter of fig. 3 will be 12 + 8 units=20 units.
The perimeter is 2(n + 1), where n is the number of squares present.
By counting all the outer sides of the figure, taking 1 side=1 unit, we get its perimeter as 20.
F i g . 1 : P = 4 ⟹ ( 4 ⋅ 1 )
F i g . 2 : P = 1 2 ⟹ ( 4 ⋅ 3 )
F i g . 3 : P = 4 ⟹ ( 4 ⋅ 5 )
⋮
Having noticed this:
n = n u m b e r o f a r r o w s , f ( n ) = p e r i m e t e r
Then:
f ( n ) = 4 n
The simple way to do this is simply counting the edges
That is better
Or count the edges on one of the four parts jutting out, then multiply by 4
perimeter figure 1 = 1*4
figure 2 = 3*4
figure 3 = 5*4
y = (2x-1)4
or you could just count the number of edges sticking out on one of them sticks and times it by 4. 1 4 3 4 5*4
That is a nice solution Marion Edith from mpesa foundation academy
4 sides with 5 units each. 4 x 5 = 20
it is also 12 unit peremeter
4 boxes have 3 sides, and 4 have 2 sides. Therefore (3 x 4) + (2 x 4) = 20
Different approach to
We can find the solution with this formula P=n.4-(n-1).2
where n is the number of squares :)
For figure n, it simplifies down to p ( n ) = 4 ∗ ( 2 n − 1 ) . Here, the value is simply p ( 3 ) = 4 ∗ ( 2 ( 3 ) − 1 ) , which is 20.
In fig. 1 the unit of edge is 4unit and the fig.2 the unit of edge is 8unit.. It means that when the blocks are increased the no. Will also be increased. It increases by multiple of 4 b/w the 2 gaping..ex.4×3=12,4×5=20 so total block of perimeter is 4 +8+8=20 i.e p= 2n+2
Since the first figure has 4 units, the second one has12 units, this means that they were getting the perimeter of the figures and this meant that one side of the square has 1 unit. If you count the sides in figure 3 you will be able to find out that they are 20 which means you don't count those that are attached on the sides.Marion Edith from Mpesa foundation academy.
AT LAST YOU GET YOUR ANSWER AS=20
Nic e solution
Find the length from 1 end to other and multiply into 4
Every time a box is added it increases the length of each arm by one unit or the perimeter increases by 2 units. For four boxes it increases by 8 units and so the answer is 12+8=20.
Each side block is of 5 units ,so four sides will have 20 Ans
every time there will be increment of 8 units (3*4-4)
Take Fig. 1. The Square is having 4-Sides and each side is 1-Unit in length and so the Periphery of square is 4-Units. In big Cross, 9 Squares are included so the total Periphery of 9 squares will be 36 Units. But in the Fig. 3, there are 16 Sides of 9 squares which are not Part of Periphery, so 36 - 16 = 20 sides, which are making the Periphery of Fig. 3. Thus Periphery will be 20 Units.
we can't count like this 1 2 3 4 . . . . . . . . . we need even numbers. 2 4 6 8 . . . . . . . . . . so on. and if we do this y = d. then we could just make 2 again. crazy mathimatics. right! but its y thats 2.
24681012141820
It is given that the square one has a perimeter of 4 units.This means that each side of the square measures 1 unit.So in the last figure we just have to count the number of edges of each square.
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When a new box is added at one of the "ends" of figure 2, it adds exactly 2 new edges:
Since 4 boxes are added, the perimeter change is +8, so 1 2 + 8 = 2 0 .