#### Answer

Perimeters:
$P1 = 36cm$
$P2 = 24cm$
Areas:
$A1 = 62.4cm^2$
$A2 = 27.6cm^2$

#### Work Step by Step

As the first triangle has all the sides of $12cm$ then all the sides of the second triangle are of $8cm$. The rate is $\frac{12}{8} = \frac{3}{2}$, then the height of the second triangle is $\frac{10.4*2}{3} = 6.9cm$.
Perimeters:
$P1 = 12 + 12 + 12 = 36cm$
$P2 = 8 + 8 + 8 = 24cm$
Areas:
$A1 = \frac{12*10.4}{2} = 62.4cm^2$
$A2 = \frac{8*6.9}{2} = 27.6cm^2$