▁W ords : ▁M oll we ide ' s ▁Equ ation ", ▁Mathemat ics ▁Magazine , ▁volume ▁ 6 1 , ▁number ▁ 5 , ▁page ▁ 2 8 1 , ▁December , ▁ 1 9 8 8 . ▁ ▁Category : Tr ig on ometry ▁Category : Tri angle ▁geometry <0x0A> </s> ▁Touch Pal ▁is ▁an ▁alternative ▁input ▁method ▁for ▁mobile ▁devices , ▁designed ▁and ▁developed ▁by ▁Shang hai - based ▁Co o T ek . ▁It ▁is ▁a ▁software ▁application ▁running ▁on ▁multiple ▁platforms , ▁including ▁Android , ▁iOS ▁( no ▁longer ▁supported , ▁only ▁maintained ), ▁Windows ▁Mobile , ▁and ▁Windows ▁ 8 . ▁It ▁sim ul ates ▁a ▁keyboard ▁on ▁the ▁screen ▁of ▁the ▁device , ▁which ▁is ▁used ▁to ▁enter ▁text ▁by ▁t apping ▁on ▁the ▁screen ▁or ▁sl iding ▁a ▁finger ▁between ▁letters ▁construct ing ▁the ▁word . ▁It ▁is ▁an ▁optional ▁text ▁input ▁method ▁to ▁the ▁traditional ▁physical ▁key boards ▁and ▁default ▁key boards ▁provided ▁by ▁the ▁device ▁manufact urer . ▁ ▁Technology ▁ ▁Touch Pal ▁default ▁keyboard ▁layout ▁is ▁designed ▁based ▁on ▁the ▁" T +" ▁technology ▁that ▁comb ines ▁two ▁letters ▁and ▁one ▁symbol ▁on ▁each ▁key , ▁whose ▁layout ▁looks ▁like ▁a ▁T . ▁The ▁overall ▁layout ▁of ▁all ▁the ▁letters ▁follows ▁a ▁common ▁computer ▁keyboard ▁layout , ▁which ▁is ▁the ▁Q W ER TY ▁layout . ▁▁ ▁It ▁has ▁a ▁word ▁predict ing ▁technology ▁which ▁predict s ▁the ▁most ▁probable ▁word ▁or ▁its ▁sp elling . ▁ ▁Ad ▁practices ▁ ▁In ▁June