Answer:
the largest angle of the field is 149⁰
Step-by-step explanation:
Given;
perimeter of the triangular filed, P = 120 m
length of two known sides, a and b = 21 m and 40 m respectively
The length of the third side is calculated as follows;
a + b + c = P
21 m + 40 m + c = 120 m
61 m + c = 120 m
c = 120 m - 61 m
c = 59 m
B
↓ ↓
↓ ↓
↓ ↓
A → → → → → → → → → → → C
Consider ABC as the triangular field;
Angle A is calculated by applying cosine rule;
![a^2 = b^2 + c^2 - 2bc \ Cos A\\\\Cos \ A = \frac{b^2 + c^2 - a^2}{2bc} \\\\Cos \ A = \frac{40^2 + 59^2 - 21^2}{2 \times 40 \times 59} \\\\Cos \ A = 0.983\\\\A = Cos ^{-1} (0.983)\\\\A = 10.6 \ ^0](https://tex.z-dn.net/?f=a%5E2%20%3D%20b%5E2%20%2B%20c%5E2%20-%202bc%20%5C%20Cos%20A%5C%5C%5C%5CCos%20%5C%20A%20%3D%20%5Cfrac%7Bb%5E2%20%2B%20c%5E2%20-%20a%5E2%7D%7B2bc%7D%20%5C%5C%5C%5CCos%20%5C%20A%20%3D%20%5Cfrac%7B40%5E2%20%2B%2059%5E2%20-%2021%5E2%7D%7B2%20%5Ctimes%2040%20%5Ctimes%2059%7D%20%5C%5C%5C%5CCos%20%5C%20A%20%3D%200.983%5C%5C%5C%5CA%20%3D%20Cos%20%5E%7B-1%7D%20%280.983%29%5C%5C%5C%5CA%20%3D%2010.6%20%5C%20%5E0)
Angle B is calculated as follows;
![Cos \ B = \frac{a^2 + c^2 - b^2}{2ac} \\\\Cos \ B = \frac{21^2 + 59^2 - 40^2}{2 \times 21 \times 59} \\\\Cos \ B = 0.937\\\\B= Cos ^{-1} (0.937)\\\\B = 20.5 \ ^0](https://tex.z-dn.net/?f=Cos%20%5C%20B%20%3D%20%5Cfrac%7Ba%5E2%20%2B%20c%5E2%20-%20b%5E2%7D%7B2ac%7D%20%5C%5C%5C%5CCos%20%5C%20B%20%3D%20%5Cfrac%7B21%5E2%20%2B%2059%5E2%20-%2040%5E2%7D%7B2%20%5Ctimes%2021%20%5Ctimes%2059%7D%20%5C%5C%5C%5CCos%20%5C%20B%20%3D%200.937%5C%5C%5C%5CB%3D%20Cos%20%5E%7B-1%7D%20%280.937%29%5C%5C%5C%5CB%20%3D%2020.5%20%5C%20%5E0)
Angle C is calculated as follows;
![Cos \ C = \frac{a^2 + b^2 - c^2}{2ab} \\\\Cos \ C = \frac{21^2 + 40^2 - 59^2}{2 \times 21 \times 40} \\\\Cos \ C = -0.857\\\\C = Cos ^{-1} (-0.857)\\\\C = 149\ ^0](https://tex.z-dn.net/?f=Cos%20%5C%20C%20%3D%20%5Cfrac%7Ba%5E2%20%2B%20b%5E2%20-%20c%5E2%7D%7B2ab%7D%20%5C%5C%5C%5CCos%20%5C%20C%20%3D%20%5Cfrac%7B21%5E2%20%2B%2040%5E2%20-%2059%5E2%7D%7B2%20%5Ctimes%2021%20%5Ctimes%2040%7D%20%5C%5C%5C%5CCos%20%5C%20C%20%3D%20-0.857%5C%5C%5C%5CC%20%3D%20Cos%20%5E%7B-1%7D%20%28-0.857%29%5C%5C%5C%5CC%20%3D%20149%5C%20%5E0)
Therefore, the largest angle of the field is 149⁰.
Answer:
Step-by-step explanation:
<u>Sum of n terms formula:</u>
<u>Solving for n</u>
- 3480 = 1/2n(9 + 165)
- 3480 = 87n
- n = 3480/87
- n = 40
All of them have the same answer of -8 except the last one.
Answer:
what are the choices
Step-by-step explanation:
4X-4Y>28
X-Y>7 both side divide by 4