We will use the ratio method to solve this question
∵ A giraffe is 18 feet tall
∵ The shadow of it is 12 feet
∵ Corry casts a shadow 4 feet
→ By using the ratio method
→ Tall: Shadow
→ 18 : 12
→ h : 4
→ By using cross multiplication
∵ h x 12 = 18 x 4
∴ 12h = 72
→ Divide both sides by 12 to find h
∴ h = 6
∴ Corry is 6 feet tall