There is a formula which employs the use of determinants and which helps us calculate the area of a triangle if the vertices are given as 
. The formula is as shown below:
Area=
Now, in our case, we have: 
, and
Thus, the area in this case will become:
Area=
Therefore, Area=![\frac{1}{2}\times [[3(-1\times 1-(-5)\times 1]-3[3\times 1-(-2)\times 1]+1[3\times -5-2]]= \frac{1}{2}\times -20=-10](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7D%5Ctimes%20%5B%5B3%28-1%5Ctimes%201-%28-5%29%5Ctimes%201%5D-3%5B3%5Ctimes%201-%28-2%29%5Ctimes%201%5D%2B1%5B3%5Ctimes%20-5-2%5D%5D%3D%20%5Cfrac%7B1%7D%7B2%7D%5Ctimes%20-20%3D-10)
We know that area cannot be negative, so the area of the given triangle is <u>10 squared units</u>.
Answer:
The answer is B
Step-by-step explanation:
You have to seperate the inequalities into 2 :
Then you have to solve it :
The area is 60m squared.
The formula for a triangle is base times height, divided by 2. Base times height in this case is 10m x 12m, which is 120m. 120m divided by 2 is 60m squared. (It is squared because it is not just a length, but an area of a flat shape.)
