Answer:
Area of triangle is 9.88 units^2
Step-by-step explanation:
We need to find the area of triangle
Given E(5,1), F(0,4), D(0,8)
We will use formula:

We need to find the lengths of side DE, EF and FD
Length of side DE = a = 
Length of side DE = a = 
Length of side EF = b = 
Length of side EF = b = 
Length of side FD = c = 
Length of side FD = c = 
so, a= 8.60, b= 5.8 and c = 4
s = a+b+c/2
s= 8.6+5.8+4/2
s= 9.2
Area of triangle=
So, area of triangle is 9.88 units^2
Here is an example:
Josh bought 7 apples for $21.
21/7 is 3, so one apple costs $3. This is the unit rate.
21/7 simplifies to 3/1, that’s another way to think about it. Simplify the fraction until the denominator is 1.
Hope this helps! Tell me if you have any questions!
Make the denominator the same, so multiple 3/10 by 2, which produces 6/20. Take 6/20 and subtract 7/20 because adding a negative number is the same as subtracting a positive number. the Answer is -1/20.