Question

Selembar kertas berbentuk layang - layang. luasnya sama dengan 720 cm. perbandingan diagonal - diagonalnya adalah 2 : 5. hitunglah panjang masing - masing diagonalnya.

pake cara!

Answer 1

720 = 2x.5x
             2
1440 = 10x²
1440/10 = x²
144 = x²
12 = x
diagonal 1 = 2x = 2.12 = 24
diagonal 2 = 5x = 5.12 = 60

Answer 2

Luas layang -layang = (diagonal1 ×diagonal2) ÷2
Diagonal 1 = 5*x = 5x
Diagonal 2 = 2*x = 2x
Luas layang-layang =
(5x × 2x)  ÷2 = 720 cm²
5x × 2x = 720 × 2 
5x × 2x = 1440
10.x² =  1440
x² = 1440 ÷ 10
x² = 144
x = 12 cm

Maka,
diagonal 1 = 5*x = 5×12 = 60cm
diagonal 2 = 2*x = 2×12 = 24cm