2. In the figure given, what are the values of La? А a (35° 46° bº B cº D С C E (a) 92 (c) 20° (b) 18° (d) 15°
Answers
Answer:
18 is the answer
please make me as a brainlist
- ∠a is equal to 18° .
To Find :- In the figure given, what are the values of ∠a ?
(a) 92° (b) 20° (c) 18° (d) 15°
Concept used :-
- Sum of all three angles of a triangle is equal to 180° .
- Angle opposite to equal sides of a triangle are equal in measure .
- Exterior angle of a traingle is equal to sum of opposite interior angles .
Solution :-
In ∆ABD,
→ AB = BD
So,
→ ∠ADB = ∠DAB { Angle opposite to equal sides of a triangle are equal in measure . }
then,
→ ∠ABC = ∠ADB + ∠DAB { Exterior angle is equal to sum of opposite interior angles . }
→ ∠ABC = 35° + 35°
→ ∠ABC = 70°
→ ∠b = 70° -------- Equation (1)
Similarly,
In ∆ACE,
→ AC = CE
So,
→ ∠AEC = ∠CAE { Angle opposite to equal sides of a triangle are equal in measure . }
then,
→ ∠ACB = ∠AEC + ∠CAE { Exterior angle is equal to sum of opposite interior angles . }
→ ∠ACB = 46° + 46°
→ ∠ACB = 92°
→ ∠c = 92° --------- Equation (2)
Now in ∆ABC,
→ ∠ABC + ∠ACB + ∠CAB = 180° { Angle sum property of a triangle }
→ ∠b + ∠c + ∠a = 180°
putting values from Equation (1) and (2),
→ 70° + 92° + ∠a = 180°
→ 162° + ∠a = 180°
→ ∠a = 180° - 162°
→ ∠a = 18° (Ans.)
Hence, Option (c) 18° is correct answer .
Learn more :-
In the figure along side, BP and CP are the angular bisectors of the exterior angles BCD and CBE of triangle ABC. Prove ∠BOC = 90° - (1/2)∠A .
https://brainly.in/question/32333207