Mathematics Question and Solution
9 = 8-8cosa
8cosa = -1
a = acos(-1/8)
a = 97.18075578146°
Therefore;
a• = 180-a
a• = 180-97.18075578146
a• = 82.81924421854°
b = ½(180-82.81924421854)
b = 48.59037789073°
c = ½(48.59037789073)
c = 24.29518894536°
Where c is alpha.
sin24.29518894536 = d/4
d = 1.64575131106 cm.
cos24.29518894536 = e/4
e = 3.64575131106 cm.
f = 90-24.29518894536
f = 65.70481105464°
Red area is;
0.5*1*1.64575131106sin65.70481105464
= ¾ cm²
Blue area is;
2(0.5*3.64575131106*1.64575131106)-(¾)
= 6-(3/4)
= ¼(24-3)
= ¼(21) cm²
It implies;
Area Blue : Area Red is;
¼(21) ÷ (3/4)
= 21/3
= 7/1
= 7:1
