(1) The remainder of an angle of 72 degrees and 20 'is equal to? 25 degrees and the complement of an angle of 31' is equal to? (2) the known angle (alpha, like a) is If the angle (beta, like scraping ear) is 2 times, and the remainder of angle alpha is 2 times equal to angle beta, then angle alpha = angle beta =?

(1) The remainder of an angle of 72 degrees and 20 'is equal to? 25 degrees and the complement of an angle of 31' is equal to? (2) the known angle (alpha, like a) is If the angle (beta, like scraping ear) is 2 times, and the remainder of angle alpha is 2 times equal to angle beta, then angle alpha = angle beta =?

(1) 90 ° - 72 ° 20 ′ = 17 ° 40 ′ 180 ° - 25 ° 31 ′ = 154 ° 29 ′; (2) α = 2 ∠ β (1), (90 ° - α) × 2 = β (2) substitute (2) to get (90 ° - 2 ∠ β) × 2 = β 180 ° - 4 ∠ β = β 5 ∠ β = 180 ∠ β = 36 °, α≈ 2 ∠ β = 72 ° 3