Question

Find the value of y.​

Answer 1

Answer:

=6√3 the third option.

Step-by-step explanation:

We can use the Pythagoras theorem to find the value of y. We need two equations that include y.

a²+b²=c²

c=9+3=12

x²+y²=12²

x²=144 - y².........i (This is the first equation)

We can also express it in another way but let us find the perpendicular dropped to c.

perpendicular²= x²-3²=x²-9 according to the Pythagoras theorem.

y²=(x²-9)+9²

y²=x²+72

x²=y²-72....ii( this is the second equation

Let us equate the two.

y²-72=144-y²

2y²=144+72

2y²=216

y²=108

y=√108

In Surd form √108=√(36×3)=6√3

y=6√3