a) <A +<B= 180° b) <B+<C = 180°
30° +<B = 180° 4•<C +d <C = 180°
<B= 180°- 30° 5•<C = 180°
<B= 150° <C= 36°
<A=<C= 30° <C=<A
<B=<D= 150° <B= 4•36= 144°
<B=<D = 144°
c)<C+<B= 180° d)<DBA=25°
20/100•<B +<B = 180° <B=<D= 25°
<A+<B= 180° => <A= 180- 25° d) <A = 155°
i) <A+<B = 180°
<B+20° +<B= 180°
2•<B =180- 20°
2•<B = 160°
<B = 160°÷2
<B = 80°
coroana?
