we have been asked to find the sum of the series

As we know that a geometric series has a constant ratio "r" and it is defined as

The first term of the series is 
Geometric series sum formula is

Plugin the values we get

On simplification we get

Hence the sum of the given series is
Vertical reflection over the x-axis, shrink of 1/3, right 3, up 2
ANSWER

and

EXPLANATION
Since corresponding angles are equal,

Alternate angles are also equal, therefore,

Equation (2) minus equation (1) gives,


We put
in to equation (1)


