[
  "First find ∠GHI: in isosceles triangle, base angles = (180° − 24°) ÷ 2 = 78°.",
  "Write the ratio: 78 : 65.",
  "Simplify: divide both by their HCF (13). 78/13 = 6, 65/13 = 5. Answer: 6 : 5."
]