I have to draw an n sided polygon using an isosceles triangle function.

It should be only 3 lines inserted under def draw_pie(n, r).

Can you help me figure out how?

```
import math
import turtle
def draw_pie(n, r):
"""Draws a pie divided into radial segments.
n: number of segments
r: length of the radial spokes
"""
def isosceles(r, angle):
"""Draws an isosceles triangle.
The turtle starts and ends at the peak, facing the middle of the base.
r: length of the equal legs
angle: half of peak angle, in degrees
"""
y = r * math.sin(angle * math.pi / 180)
turtle.right(angle)
turtle.forward(r)
turtle.left(90+angle)
turtle.forward(2*y)
turtle.left(90+angle)
turtle.forward(r)
turtle.left(180-angle)
# draw a hexagonal (6-sided) pie
size = 100
draw_pie(6, size)
# wait for user to close the window
turtle.done()
```