To do this problem, you will need to know the side lengths of the triangle. If you have those, just plug them in for a, b, and c and evaluate the square root.
Here is an example. If the sides are 3, 4, 5.
It would be:

The 6 is in the formula because it is the semi-perimeter (half).
Answer:
It will be worth $1732.30.
Step-by-step explanation:
After 1 year : 6000 x .78 = 4680
2 yr - 4680 x .78 = 3650.4
3 yr - 3650.4 x .78 = 2847.312
4 yr - 2847.312 x .78 = 2220.90336
5 yr - 2220.90336 x .78 = 1732.304621
1732.30
I think this is what it was asking
5x+12-2x= 15 Answer: (1,10)
x= 1
y=12-2(1)
y= 10
Answer:
B is not necessarily true
Step-by-step explanation:
A) This is always true
B) This is not necessarily true
When two lines intersect, they form angles at the intersection as D says, but that does not mean that the angle will always be 90 degrees as is required for the two intersecting lines to be perpendicular
C) This is always true
D) This is always true