Keliling belah ketupat ABCD = 80cm, panjang diagonalnya AC =24cm. Luah belah ketupat adalah...

K=4s
80=4s
s=80/4
s=20 cm

1/2BD²=(s²-(1/2AC)²)=(20²-(1/2.24)²)=(400-12²)=(400-144)=(256)
1/2BD=√256
1/2 BD=16
BD=2.16=32 cm

L=1/2(d1.d2)=1/2(24.16)=1/2.384=192 cm²