Determine if these sides form a triangle
4√5 = 8.94
√145 = 12.04
So
8.94 + 12.04 > 19
8.94 + 19 > 12.04
12.04 + 19 > 8.94
These sides can form a triangle
Now you need to see what kind of triangle
a^2 = (4√5)^2 = 16 x 5 = 80
b^2 = (√145)^2 = 145
c^2 = (19)^2 = 361
If
c^2 < a^2 + b^2 = acute
c^2 > a^2 + b^2 = obtuse
c^2 = a^2 + b^2 = right
In this case c^2 = 361 > a^2 + b^2 = 80 + 145 = 225
So it's an obtuse triangle
Answer:
C. obtuse
