Answer:
=2√2 the fourth choice.
Step-by-step explanation:
We can use the Pythagoras theorem to calculate the value of y.
a²+b²=c²
a=1
b=y
c=3
Therefore substituting for the values in the theorem above we get:
1²+y²=3²
Leave y on one side.
y²=3²-1²
y²=9-1
y²=8
y=±2√2 in surd form.
Since we expressing length, a scalar quantity, we take the modulus of our answer. Thus y=2√2
