an equilateral triangle of side 9cm is inscribed in a circle. find radius
Answers
Answered by
25
aloha!
⊱ ────── {⋅. ✯ .⋅} ────── ⊰
given: AC=AB=BC= 9 cm
to find: the radius.
construction: draw AD being the perpendicular bisector of side BC.
proof: we know that that ∠ADC would be equal to 90° by construction.
And BD = DC
Now,
∠B = 60° { given }
∠OBD = 30° { half of 60° as BO bisects ∠B }
in triangle OBD
cos 30° =
√3 / 2 =
H = 3√3 cm.
⊱ ────── {⋅. ✯ .⋅} ────── ⊰
⊱ ────── {⋅. ✯ .⋅} ────── ⊰
given: AC=AB=BC= 9 cm
to find: the radius.
construction: draw AD being the perpendicular bisector of side BC.
proof: we know that that ∠ADC would be equal to 90° by construction.
And BD = DC
Now,
∠B = 60° { given }
∠OBD = 30° { half of 60° as BO bisects ∠B }
in triangle OBD
cos 30° =
√3 / 2 =
H = 3√3 cm.
⊱ ────── {⋅. ✯ .⋅} ────── ⊰
Attachments:
Answered by
1
may this answer will help you
Attachments:
Similar questions