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Fantezi Geometri => Fantezi Geometri => Konuyu başlatan: Speed2001 - Kasım 22, 2010, 11:16:59 öö

Başlık: TII-(72 24 x) {solved}
Gönderen: Speed2001 - Kasım 22, 2010, 11:16:59 öö

 8)
(http://img217.imageshack.us/img217/2980/geo7224.jpg)

Başlık: Ynt: TII-(72 24 x)
Gönderen: Lokman Gökçe - Kasım 24, 2010, 09:17:16 ös

x = 72^o. I used similar approach at http://geomania.org/forum/fantezi-geometri/tii-(36-12-x)/msg7433/?topicseen#msg7433

Let's apply sine theorem at triangle ABC. Therefore BC = sin72/sin24 and AC = sin84/sin24.

We show that BC² = CD.AC. Hence line BC is tangent to circumcircle of triangle ABD. so x = m(CBD) = m(BAD) = 72^o.

Saludos