Final answer:
The estimated involved body surface area of the thermal burn on the anterior right leg is 18%.
Step-by-step explanation:
The estimated involved body surface area of the thermal burn on the anterior right leg can be determined using the Rule of Nines. According to the Rule of Nines, each leg accounts for 18% of the total body surface area. Since the burn involves the entire surface of the anterior right leg, the estimated involved body surface area would be 18%.