Question

последние задание ыф

Answer 1

$\displaystyle\bf\\AB=29\\\\BC=20$

По теореме Пифагора :

$\displaystyle\bf\\AB^{2} =BC^{2} +AC^{2}\\\\AC^{2} =AB^{2} -BC^{2} =29^{2} -20^{2} =(29-20)(29+20)=9\cdot 49\\\\AC=\sqrt{9\cdot 49} =3\cdot 7=21\\\\\boxed{AC=21}\\\\\\Ctg < B=\frac{BC}{AC} =\frac{20}{21} \\\\\\\boxed{Ctg < B=\frac{20}{21} }$