已知∠α与∠β互余,且∠α比∠β小25°,求2∠α-1/3∠β的值

Question

已知∠α与∠β互余,且∠α比∠β小25°,求2∠α-1/3∠β的值

Answer 1

相加等于90°的两角称作互为余角
∠α+∠β=90°
∠β-∠α=25°
所以
2∠β=90+25=115°
∠β=115°/2
2∠α=90-25=65°
2∠α-1/3∠β
=65-115/2÷3
=65-115/6
=175/6
=29°10‘