Question Number 170502 by cortano1 last updated on 25/May/22
Answered by som(math1967) last updated on 25/May/22
Commented by som(math1967) last updated on 25/May/22
$$\angle{DEC}=\mathrm{90} \\ $$$$\angle{ECD}=\mathrm{90}−\mathrm{15}=\mathrm{75} \\ $$$$\angle{EAC}=\mathrm{180}−\mathrm{75}=\mathrm{105}\bigstar \\ $$$$\:\angle{ABD}=\theta=\mathrm{180}−\mathrm{105}−\mathrm{55}=\mathrm{20} \\ $$$$\bigstar{AECD}\:{cyclic} \\ $$$$ \\ $$
Commented by JDamian last updated on 25/May/22
why do you assume that CD is the diameter of a circle?
Commented by som(math1967) last updated on 25/May/22
$${I}\:{assume}\:{from}\:{the}\:{diagram} \\ $$$${if}\:{CD}\:{is}\:{chord}\:\left({not}\:{dia}\right)\:{then}\: \\ $$$${please}\:{give}\:{any}\:{solution} \\ $$
Commented by mr W last updated on 25/May/22
$${there}\:{is}\:{unique}\:{solution}\:{only}\:{if} \\ $$$${CD}\:{is}\:{diameter}. \\ $$
Answered by mr W last updated on 25/May/22
