Question

3) Calcule o perimetro do triângulo retângulo ABC da figura, sabendo que, BC = 10m e cos d=0, 6. ​

Answer 1

$\boxed{\begin{array}{l}\sf cos(d)=\dfrac{CA}{CB}\\\sf0,6=\dfrac{CA}{10}\\\sf CA=10\cdot0,6=6~m\\\sf CB^2=CA^2+AB^2\\\sf AB^2=CB^2-CA^2\\\sf AB^2=10^2-6^2\\\sf AB^2=100-36\\\sf AB^2=64\\\sf AB=\sqrt{64}\\\sf AB=8~m\\\sf P= CB+CA+AB\\\sf P=10+6+8\\\huge\boxed{\boxed{\boxed{\boxed{\sf P=24~m}}}} \end{array}}$