Mathematics Question and Solution
Let BC be 1 unit.
a = ½(180-45)
a = ½(135)
a = 67.5°
a is angle ABC = angle ACB.
(1/sin45) = (b/sin67.5)
b = 1.3065629649 units.
b is AB.
c = 180-45-67.5
c = 67.5°
c is angle BEC.
It implies;
BE = 1 unit.
d = 67.5-30
d = 37.5°
d is angle BCD.
e = 180-67.5-37.5
e = 75°
e is angle BDC.
(1/sin75) = (f/sin37.5)
f = 0.630236207 units.
f is BD.
g = 67.5-45
g = 22.5°
g is angle DBE.
h² = 1²+0.630236207²-2*1*0.630236207cos22.5
h = 0.4823619098 units.
h is DE.
Therefore, the required angle ? is;
Let it be j.
(0.630236207/sinj) = (0.4823619098/sin22.5)
j = 30°
Again, j is the required angle (?).
