Răspuns:
[tex]\boldsymbol {\red{\dfrac{3}{5};\dfrac{3}{4}}}[/tex]
Explicație pas cu pas:
[tex]AC = \sqrt{AD^2+DC^2} = \sqrt{ {12}^{2} + {16}^{2} } = \sqrt{400} = 20 \ cm \\ [/tex]
[tex]\cos \widehat {CAD} = \dfrac{AD}{AC} = \dfrac{12}{20} = \bf \dfrac{3}{5}[/tex]
AD² = BD×DC ⇒ 12² = BD×16 ⇒ BD = 9 cm
[tex]ctg \ \widehat {ABC} = ctg \ \widehat {ABD} = \dfrac{BD}{AD} = \dfrac{9}{12} = \bf \dfrac{3}{4} \\ [/tex]
Răspuns:
Explicație pas cu pas:
AC²=12²+16²=144+256=400 ; AC=√400= 20 cm; AC²=BC*DC ; 400=²16*BC ; BC=400/16=25 cm ; BD=25-16=9 cm; AB²=9²+12²=81+144=225 ; AB=√225=15 cm ; cos CAD=12/20=3/5 ;ctgABC=9/12=3/4 ;
