Question

No paralegrama ABCD,NA =ND.Determine.
Ajuda ai !!

Answer 1

 Ora, se NA = ND e o triângulo é retângulo, então os ângulos do triângulo AND valem 45°. Daí,

a)

$\sin45^o=\frac{x}{40}\\\\\frac{\sqrt{2}}{2}=\frac{x}{40}\\\\2x=40\sqrt{2}\\\\\boxed{x=20\sqrt{2}\,\text{cm}}$

b)

$S=b\cdot\,h\\\\S=60\cdot20\sqrt{2}\\\\\boxed{S=1200\sqrt{2}\,\text{cm}^2}$

c)

$S_t=\frac{AN\cdot\,ND}{2}\\\\S_t=\frac{20\sqrt{2}\cdot20\sqrt{2}}{2}\\\\\boxed{S_t=800\text{cm}^2}$