Answer:
The farmer would need 80 posts.
Step-by-step explanation:
If one side of the garden is 10m long, and the garden is a square, we can assume that all 4 sides will be 10m. That makes it 40m in total. Times 40×2 and you get 80.
the triangle is not a right angle
5²+12²=169
15²=225
Negative x positive = negative
Negative x negative = positive
-4 x 8 = -32
-4 x -1 = 4
-4 x -5 = 20
-4 x 9 = -36
Answer: |-32 4 20 -36|