7.71 feet is your answer.
Answer:
A ≈ 2 ft²
Step-by-step explanation:
The area (A) of a triangle using Heron's formula is
A = 
where s is the semiperimeter and a, b , c the sides of the triangle.
s =
=
=
= 4.5
Then
A = 
= 
= 
≈ 1.9843...
= 2 ft² ( to the nearest square foot )
Answer:
8N - 4 border tiles.
Step-by-step explanation:
There are 4 border tiles in each corner and between the tiles there are N-2 tiles along the 4 sides.
So the number of border tiles
= 4+ 4(N - 2)
= 4 + 4N - 8
= 8N - 4.