In figure 3.98, seg AB is a diameter of a circle with centre O. The bisector of ∠ACB intersects the circle at point D. Prove that, seg AD ≅ seg BD. Complete the following proof by filling in the blanks.
In figure 3.98, seg AB is a diameter of a circle with centre O. The bisector of \(\angle ACB\) intersects the circle at point D. Prove that, seg AD ≅ seg BD. Complete the following proof by filling in the blanks.
Figure: C and D lie on opposite sides of diameter AB.
Proof: Draw seg OD.
\(\angle ACB\) = □ ………. angle inscribed in semicircle
\(\angle DCB\) = □ ………. CD is the bisector of \(\angle C\)
m(arc DB) = □ ………. inscribed angle theorem
\(\angle DOB\) = □ ………. definition of measure of an arc (I)
seg OA ≅ seg OB ………. □ (II)
\(\therefore\) line OD is □ of seg AB ………. From (I) and (II)
\(\therefore\) seg AD ≅ seg BD