Question

Um terreno retangular tem 80m de perimetro e 300m² de area. As medidas desse terreno sao:

Answer 1

A+B+C+D = 80
A= B
C= D
2A+2D=80 (I)

A*D=300 (II)
A=300/D

2.300/D + 2.D= 80
600/D + 2.D=80
600/D + 2D²/D = 80D/D
600+2D²=80D
2D²-80D+600=0
Dividindo por 2

D²-40D+300=0

Δ=40²-4*1*300
Δ=1.600-1.200
Δ=400

40+-√400/2

40+20/2
D=30

40-20/2
D'=10

30x10