Answer:
36 inches
Explanation:
Perimeter of the larger triangle: P1
Perimeter of the smaller triangle: P2
It's probably a right angle triangle. Verifying through pythagoras theorem:
20² = 12² + 16²
400 = 144 + 256
P1 = 20+12+16 = 48
P1/P2 = side1/side2
48/P2 = 16/12
48/P2 = 4/3
P2 = 48 × 3/4
P2 = 36