Ip. ABC triunghi
{<A,<B,<C,<D} d.p {4,5,3}
DC|BC
AD|BC
Triunghiul ABC
=> <A supra 5= <B supra 5=<C supra 3=K
<A =4K
<B=5K
<C=3K
<A+<B+<C=180°
=> 180°÷12=15
<A=4K•15=60
<B=5K•15=75
<C=3K•15=45
<BAC=60°
<ABC=75°
<ACB=45°
ABC-patrulater conex
<ABC=75°
<BCD=90°
AD|B
DC|BC} => AD|CA
=> < ADC=90°
<BAD+<ADC+<DCB+<ABC=360°
<BAD+90°+90°+75°=360°
=>"<BAD=360°-255
<BAD=105°
Ps:| = perpendicular nu am gggggasit semnul sper ca te am ajutat
