Question

num triângulo ABC,os catetos são b=15cm e c=20cm. calcule o seno,cosseno e tangente dos ângulos B e C,que são opostos respectivamente aos lados b e c (faça a figura)​

Answer 1

$\Large\boxed{\begin{array}{l}\underline{\rm Observe\,a\,figura\,que\,eu\,anexei}\\\sf x^2=15^2+20^2\\\sf x^2=225+400\\\sf x^2=625\\\sf x=\sqrt{625}\\\sf x=25\,cm\\\sf sen(B)=\dfrac{20}{x}\\\\\sf sen(B)=\dfrac{20\div5}{25\div5}\\\\\sf sen(B)=\dfrac{4}{5}\end{array}}$

$\Large\boxed{\begin{array}{l}\sf cos (B)=\dfrac{15\div5}{25\div5}\\\\\sf cos(B)=\dfrac{3}{5}\\\\\sf tg(B)=\dfrac{20\div5}{15\div5}\\\\\sf tg(B)=\dfrac{4}{3}\end{array}}$

$\Large\boxed{\begin{array}{l}\sf sen(C)=cos(B)=\dfrac{3}{5}\\\\\sf cos(C)=sen(B)=\dfrac{4}{5}\\\\\sf tg(C)=\dfrac{1}{tg(B)}=\dfrac{3}{4}\end{array}}$