Final answer:
Anwar Sadat was the 3rd President of Egypt from 1970 until his assassination in 1981, known for signing the Camp David Accords.
Step-by-step explanation:
The 3rd President of Egypt during the period 1970-81 was Anwar Sadat. He assumed office after the death of Gamal Abdel Nasser in 1970 and was the Egyptian head of state until his assassination in 1981. Sadat's presidency witnessed significant events including the signing of the Camp David Accords in 1978, which was a major step in the peace process between Egypt and Israel. Sadat's efforts to foster peace with Israel were controversial among many Egyptians and contributed to his assassination.