In $$\triangle ABC, \angle B=60^\circ$$, and $$\angle C=40^\circ$$, AD and AE are respectively the bisector of $$\angle A$$ and perpendicular on BC. The measure of $$\angle EAD$$ is:
Given : AD is angle bisector of $$\angle$$ A and AE is perpendicular to BC.
To find : $$\angle$$ EAD = ?
In $$\triangle$$ ABC,
=>Â $$\angle$$Â A +Â $$\angle$$Â B +Â $$\angle$$Â C = $$180^\circ$$
=>Â $$\angle$$Â A + $$60^\circ+40^\circ=180^\circ$$
=>Â $$\angle$$Â A = $$180^\circ-100^\circ=80^\circ$$
$$\because$$Â $$\angle$$Â BAD =Â $$\angle$$Â CAD
=>Â $$\angle$$Â CAD = $$\frac{80}{2}=40^\circ$$
Using external angle property, =>Â $$\angle$$Â ADE =Â $$\angle$$Â CAD +Â $$\angle$$Â C
=>Â $$\angle$$Â ADE = $$40^\circ+40^\circ=80^\circ$$
$$\therefore$$ In $$\triangle$$ EAD,
=>Â $$\angle$$Â EAD +Â $$\angle$$Â ADE +Â $$\angle$$Â DEA = $$180^\circ$$
=>Â $$\angle$$Â EAD + $$80^\circ+90^\circ=180^\circ$$
=>Â $$\angle$$Â EAD = $$180^\circ-170^\circ=10^\circ$$
=> Ans - (D)
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