Mathematics Question and Solution
Calculating r, radius of the circle.
a = (r-4) units.
b = a+r
b = (r-4)+r
b = 2r-4
b = 2(r-2) units
It implies;
4*2(r-2) = 8*c
c = (r-2) units.
d = 8+c
d = 8+(r-2)
d = (6+r) units.
Calculating r.
11²+(6+r)²-2*11(6+r)cos60 = r²+r²-2*r*rcos120
121+36+12r+r²-66-11r = 3r²
91+r = 2r²
2r²-r-91 = 0
2r²-14r+13r-91 = 0
2r(r-7)+13(r-7) = 0
(2r+13)(r-7) = 0
Therefore;
2r+13 = 0
r ≠ -½(13) units.
It implies;
r-7 = 0
r = 7 units.
Again, r is the radius of the circle.
