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Category: Geometry

Question-16409

Question Number 16409 by b.e.h.i.8.3.4.1.7@gmail.com last updated on 21/Jun/17 Commented by b.e.h.i.8.3.4.1.7@gmail.com last updated on 21/Jun/17 $$\Delta{ABC},{is}\:{equilateral}\:{and}\:'{D}',{is}\:{a}\:{point}\:{on}\:{circumcircle}\:{of}\:{A}\overset{\Delta} {{B}C}. \\ $$$${prove}\:{that}: \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:{DA}={DB}+{DC}. \\ $$ Commented…

Question-81887

Question Number 81887 by lalitchand last updated on 16/Feb/20 Commented by mr W last updated on 16/Feb/20 $${let}\:\frac{{FA}}{{BA}}={k},\:\frac{\mathrm{1}}{\mathrm{2}}<{k}<\mathrm{1} \\ $$$${DF}=\frac{{BA}}{\mathrm{2}} \\ $$$$\frac{{OD}}{{OF}}=\frac{{DF}}{{FA}}=\frac{{BA}}{\mathrm{2}×{k}×{BA}}=\frac{\mathrm{1}}{\mathrm{2}{k}} \\ $$$${i}.{e}.\:\frac{{OD}}{{OD}+{DF}}=\frac{\mathrm{1}}{\mathrm{2}{k}} \\…

Related-to-Q16140-What-if-the-three-lines-d-1-d-2-d-3-are-not-parallel-but-concurrent-

Question Number 16302 by mrW1 last updated on 20/Jun/17 $$\mathrm{Related}\:\mathrm{to}\:\mathrm{Q16140} \\ $$$$\mathrm{What}\:\mathrm{if}\:\mathrm{the}\:\mathrm{three}\:\mathrm{lines}\:\mathrm{d}_{\mathrm{1}} ,\mathrm{d}_{\mathrm{2}} ,\mathrm{d}_{\mathrm{3}} \:\mathrm{are} \\ $$$$\mathrm{not}\:\mathrm{parallel},\:\mathrm{but}\:\mathrm{concurrent}? \\ $$ Commented by b.e.h.i.8.3.4.1.7@gmail.com last updated on…

Question-16277

Question Number 16277 by b.e.h.i.8.3.4.1.7@gmail.com last updated on 20/Jun/17 Commented by b.e.h.i.8.3.4.1.7@gmail.com last updated on 20/Jun/17 $${in}\:{triangle}:{A}\overset{\Delta} {{B}C},{consteact}\:\mathrm{3}\:{equilateral} \\ $$$${triangle}\:{on}\:{each}\:{sides}. \\ $$$${prove}\:{that}:\:\:{AL}={BM}={CN}\:. \\ $$ Answered…

In-ABC-r-1-r-2-and-r-3-are-the-exradii-as-shown-Prove-that-r-1-s-a-r-2-s-b-and-r-3-s-c-Here-s-a-b-c-2-

Question Number 16214 by Tinkutara last updated on 19/Jun/17 $$\mathrm{In}\:\Delta{ABC},\:{r}_{\mathrm{1}} ,\:{r}_{\mathrm{2}} \:\mathrm{and}\:{r}_{\mathrm{3}} \:\mathrm{are}\:\mathrm{the}\:\mathrm{exradii} \\ $$$$\mathrm{as}\:\mathrm{shown}.\:\mathrm{Prove}\:\mathrm{that}\:{r}_{\mathrm{1}} \:=\:\frac{\Delta}{{s}\:−\:{a}}\:, \\ $$$${r}_{\mathrm{2}} \:=\:\frac{\Delta}{{s}\:−\:{b}}\:\mathrm{and}\:{r}_{\mathrm{3}} \:=\:\frac{\Delta}{{s}\:−\:{c}}\:.\:\mathrm{Here} \\ $$$${s}\:=\:\frac{{a}\:+\:{b}\:+\:{c}}{\mathrm{2}}\:. \\ $$ Commented…

Question-16194

Question Number 16194 by RasheedSoomro last updated on 18/Jun/17 Commented by RasheedSoomro last updated on 18/Jun/17 $$\mathrm{A},\mathrm{B}\:\mathrm{and}\:\mathrm{C}\:\mathrm{are}\:\mathrm{three}\:\mathrm{non}-\mathrm{collinear}\:\mathrm{points}. \\ $$$$\mathrm{Also}\:\mathrm{they}\:\mathrm{are}\:\mathrm{centers}\:\mathrm{of}\:\mathrm{three}\:\mathrm{circles}\:\mathrm{having} \\ $$$$\mathrm{radii}\:{a},{b}\:\mathrm{and}\:{c}\:\mathrm{respectively}.\:\mathrm{D},\mathrm{E}\:\&\:\mathrm{F}\:\mathrm{have}\:\mathrm{been}\: \\ $$$$\mathrm{taken}\:\mathrm{on}\:\mathrm{three}\:\mathrm{circles}\:\mathrm{respectively}\:\mathrm{in}\:\mathrm{such}\:\mathrm{a}\:\mathrm{way} \\ $$$$\mathrm{that}\:\bigtriangleup\mathrm{DEF}\:\mathrm{is}\:\mathrm{an}\:\mathrm{equilateral}\:\mathrm{triangle}.…