Answer:
A, C
Explanation:
The triangle inequality requires the sum of the shortest sides exceed the length of the longest side. We can find those sums to be ...
A. 8 + 17 = 25 > 23 . . . . . valid triangle
B. 7 + 14 = 21 < 23 . . . not
C. 11 + 23 = 34 > 30 . . . . . valid triangle
D. 8 + 12 = 20 < 23 . . . not
Choices A and C are valid triangles.