Mathematics Question and Solution
a = ⅕*180(5-2)
a = 108°
a is the single interior angle of the ascribed regular pentagon.
b = ½(180-108)
b = 36°
cos36 = (0.5*8)/c
c = 4.94427191 units.
d² = 2*4.94427191²-2*4.94427191²cos36
d = 3.05572809 units.
e = 0.5d
e = 1.527864045 units.
cos(0.5*108) = 1.527864045/f
f = 2.5993575699 units.
f is the radius of the inscribed circle.
Area inscribed circle is;
πf²
= π(2.5993575699²)
= 21.2266727151 square units.
