keliling tarpesium ABCD......cm

hitung panjang sisi miring
= √20² +21²
=√841
= 29
maka
keliling = 41 + 29 + 20 + 20
keliling =110 cm

cari panjang BC melalui phitagoras
EB = AB - CD
EB = 41-20
EB = 21 cm

BC² = EB² + AD²
BC² = 21² + 20²
BC² = 441 +400
BC =√841
BC = 29 cm

K = AB + BC + CD + AD
K = 41 + 29 + 20 + 20
K = 110 cm

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