Question

Find the area of triangle QRS.

Answer 1

the answer is 140. I did the assignment

Answer 2

Answer: 140 square units.

Explanation:

The area of triangle with vertices
`(x_1,y_1),(x_2,y_2)\ and\ (x_3,y_3)` is given by

`\text{Area}=(1)/(2)[x_1(y_2-y_3)+x_2(y_3-y_1)+x_3(y_1-y_2]`

Then area of triangle QRS with vertices (6,10), (2,-10) and (-9,5) is given by :-

`\\\\\Rightarrow\text{Area}=|(1)/(2)[6(-10-5)+2(5-10)-9(10-(-10))]|\\\\\Rightarrow\text{Area}=|(1)/(2)[6(-15)+2(-5)+-9(20)]|\\\\\Rightarrow\text{Area}=|(1)/(2)[280]|\\\\\Rightarrow\text{Area}=140\text{ square units}`