Answer:
5.25
Step-by-step explanation:
ok so first you add 0.75+2 which is equal to 2.75
and now you will have 8-2.75 which is equal to 5.25
Answer: The area of the triangle with the perimeter of 540 cm is approximately 10200 cm²
More exactly: 10182 cm²
Step-by-step explanation: 
240 × 84.85 = 10182
To get the height of the triangle, it takes some trigonometry;
Given 3 sides of a triangle, it is possible to calculate the angles using the Law of cosines and the formula 
We will need the measure of angle A, then use the sine of A to get the height of the line from angle C perpendicular to the base, side b.
We can use the dimensions given in the proportions and then multiply by 10 because the sides given add to a perimeter of 54, one tenth of the 540 cm of the actual triangle. The angles of the similar triangles are congruent.
side a = 19, side b = 24, side c = 11
24² + 11² - 19² is 576 + 121 - 361 = 336
2(24)(11) = 528
cos A = 336 / 528 that is 0.636364
= 50.47°
sin(50.47) = 0.77129
0.77129 × 11 = 8.48 is the height Rounding to 8.5 would be reasonable for this height
Using rounded values here to calculate Area :
85 × 240/2 = 10200 cm²
The correct answer to the above question is 3n^3/5m^2, i.e., the third option
Answer:
Incomplete question, check attachment for the necessary diagram
Step-by-step explanation:
Note in the attachment,
We have two identical straight line of lenght
L1 = L2 = 84.39m
We also have two identical semicircle or radius 36.5m to the first track lane
But this is not the radius of the circle, the radius of the circle will now be 36.5 plus the 6 track lane and we are told that one track lane is 1m, then, the track lane is 6m
So, radius = 36.5+6
r = 42.5m
Then, we need to calculate the perimeter of the semicircle using the formula of perimeter of a circle and dividing by2
P = 2πr/2
P =πr
P = 22/7 × 42.5
P = 133.57 m
Then, the arc 1 is equal to arc 2 which is equal to 133.57 m
A1 = A2 = 133.57 m
Now we have all the dimensions,
Then, the perimeter can be calculated by adding the length of the sides
The perimeter of the field = Lenght of the two straight lines plus the length of the two semicircle arc
P = L1 + L2 + A1 + A2
P = 84.39 + 84.39 + 133.57 + 133.57
P =435.923 m
So, to the nearest meter
P ≈ 436m
The perimeter of the track is 436m
