Answer:
66 diagonals, 67 triangles
Step-by-step explanation:
triangle - 0 diagonals(3-3), 1 triangle(3-2)
quadrilateral - 1 diagonal(4-3), 2 triangles(4-2)
pentagon 2 diagonal(5-3), 3 triangles (5-2)
hexagon 3 diagonals (6-3), 4 triangles (6-2)
n sides (n-3) diagonals, (n-2) triangles
69 sides 69-3 = 66 diagonals, 69-2 = 67 triangles
