Respuesta :

pythagorean theorm
for a right triangle with legs a and b and hypotnuse c (hyptonuse is longest)

a²+b²=c²

so
a leg is 8.3 and hyptonuse is 8.8

8.3²+b²=8.8²
68.89+b²=77.44
b²=8.55
b=√8.55≈2.9240383034426891720515239599699