pada gambar di bawah, diketahui segitiga Sama Kaki dengan sudut cab =90'

bc² = ab² + ac²
bc² = 10² + 10²
bc² = 100 + 100
bc² = 200
bc = √200
bc = 10√2
L ABC = AB × AC / 2
L ABC = BC × AD /2
AB × AC / 2 = BC × AD / 2
AB × AC = BC × AD
10 × 10 = 10√2 × AD
100 = 10√2 × AD
100/10√2 = AD
AD = 10/√2
AD = 10√2 × √2/√2
AD = 10√2 / 2
AD = 5√2