Question

un triunghi echilateral cu latura de 4 cm are aria ..?

Answer 1

[tex] A_{echilateral}= \frac{ l^{2}* \sqrt{3} }{4} \\ A= \frac{ (4cm)^{2}* \sqrt{3} }{4}= \frac{16 \sqrt{3} }{4}cm^2=4\sqrt{3}cm^2 [/tex]

Answer 2

l=4
l/2=2
h^2=l^2+l/2^2
h^2=16+4=20
h=2radical din 5
A= lxh/2
A= 4x2 radical din 5/2
A= 4 radical din 5