Mathematics Question and Solution
Notice.
ABCD is a square.
Let AB = 1 unit.
cos50 = a/1
a = 0.6427876097 units.
a is CE.
b = ½√(1²+1²)
b = ½√(2) units.
b = 0.7071067812 units.
b is OC.
c² = 0.7071067812²+0.6427876097²-2*0.7071067812*0.6427876097cos(50+45)
c = 0.9961946981 units.
c is OE.
(0.9961946981/sin95) = (0.6427876097/sind)
d = 40°
d is angle COE.
e = 90-d
e = 90-40
e = 50°
e is angle BOF.
Therefore, the required angle, x ( angle BFO) is;
x = 180-45-e
x = 180-45-50
x = 180-95
x = 85°
