Question

The diagram shows a regular nonagon.Find the value of y.

Answer 1

@campbell_st

Answer 2

The answer from the book is y=60

Answer 3

so a regular nonagon has an angle sum of

\[(9 -2) \times 180 = 1260\]

so 1 angle is

140 degrees

so the upper TSRQP is a pentagon

with 3 angles of 140



using the angle sum of a pentagon and the known angles

then x + y will equal

540 - 3(140) = 120 degrees

so I'd assume that y = 120/2

y = 60

hope it makes sense..