Mathematics Question and Solution
Let the three equal lengths be 1 unit.
it implies;
AB = BD = DE = 1 unit.
a² = 1²+1²-2*1*1cos100
a = 1.5320888862 units
a is AD.
c = ½(180-100)
c = 40°
c is angle ADB.
d = 180-40-40
d = 100°
d is angle ADE.
e² = 1.5320888862²+1²-2*1*1.53cos100
e = 1.969615506 units.
e is AE.
It implies;
(1.969615506/sin100) =
(1/sinf)
f = 30°
f is angle DAE.
g = 40+30
g = 70°
g is angle BAE
Therefore, the required angle x (angle ACB) is;
x+70+100 = 180
x = 180-170
x = 10°
Angle ACB = 10°
