Question

1)calculati aria unui dreptunghi cu laturile de:
a)4 cm si 8 cm; b)3,2 cm si 5 cm; c) 2 intregi si 1/4 si 6,4 cm.
2)Calculati aria unui patrat cu latura de :
a) 5 cm b) 4,7 cm c)3 intregi si 1/2
dau coroana

Answer 1

$1)a)L = 8 \: cm$

$l = 4 \: cm$

$A=L \: \times \: l$

$A=8 \times 4$

$A=32 \: {cm}^{2}$

$b)L = 5 \: cm$

$l = 3.2 \: cm$

$A=5 \times 3.2$

$A=16 \: {cm}^{2}$

$c)L = 6.4 \: cm$

$l = 2 \frac{1}{4} = \frac{2 \times 4 + 1}{4} = \frac{9}{4} = 2.25 \: cm$

$A=L \: \times \: l$

$A=6.4 \times 2.25$

$A=14.4 \: {cm}^{2}$

$2)a)l = 5 \: cm$

$A= {l}^{2}$

$A= {5}^{2}$

$A=25 \: {cm}^{2}$

$b)l = 4.7 \: cm$

$A= {l}^{2}$

$A= {4.7}^{2}$

$A=22.09 \: {cm}^{2}$

$c)l = 3 \frac{1}{2} = \frac{3 \times 2 + 1}{2} = \frac{7}{2} = 3.5 \: cm$

$A= {l}^{2}$

$A= {3.5}^{2}$

$A=12.25 \: {cm}^{2}$