Hello, careness
Edit: I read my diagram incorrectly!
21. Given: .
Find Code:
A
*
θ
* *
* *
E o *
*2θ θ*
* o D
2θ
* *
180-3θ
* *
B o * * * o C
Draw segments
. . Let
Since is isosceles: .
is an exterior angle of
. . Hence: .
Since is isosceles: .
At point D, we have: .
. .
Since is isosceles: . .[1]
But is a base angle of an isosceles triangle with vertex angle
.Hence: . .[2]
Equate [2] and [1]: .
. .
is the central angle of a regular heptagon.
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
Consider this diagram . . . Code:
A
*
/θ\
/ \
/ \
/ \
/ \ D
/ *
/ * \
/ * \
/ * \
B * - - - - - - - - - *C
Given: .Isosceles triangle
. . . . . .
Then: . , the central angle of a regular pentagon.