<span /><span><span>sorry if this answer <span>wrong
</span></span>Parabolic antenna is a device Digital FTA TV and Radio broadcast receivers that transmit it via satellite as free to air, with this device, the TV signal reception is not affected anymore by the surrounding environment such as trees, mountains and so forth.
Other advantages that we can enjoy with one of these digital devices is the quality of the resulting images and sound, no matter how good the picture and sound produced by analog antenna (antenna UHF and VHF) still can not collate the quality of picture and sound Digital Antenna Parabola. Even now there are parabolic antenna device capable of receiving broadcast digital HDTV (high-definition television)
Her general FTA Digital Satellite dish antenna consists of four main parts: 1. SOLID DISH Parabola 2. LNB (Low Noise Block Converter). 3. DiSCq (Digital Satellite Equipment Control). 4. Receiver DVB (Digital Video Broadcasting) FTA (Free To Air).</span>
1) Per prima cosa, dobbiamo trovare la misura della base più grande. Scomponendo la figura possiamo visualizzare un triangolo e un quadrato. Ci sono somiglianze con gli angoli. Quindi è un triangolo rettangolo. Applichiamo il teorema di Pitagora: