Question
find the area of a regular pentagon with radius 5in
Answers
Reiny
from the centre I can draw 5 identical triangles
the central angle of each is 360/5 or 72°
the area of one of these = (1/2)(5)(5)sin72
= 11.8882...
so 5 of them or the pentagon has an area of
appr 59.44 in^2
the central angle of each is 360/5 or 72°
the area of one of these = (1/2)(5)(5)sin72
= 11.8882...
so 5 of them or the pentagon has an area of
appr 59.44 in^2