In a triangle ABC. AB=6√3 perpendicular is drawn from point A on BC at E of length 9 and EC=3√3. Find angle A
Answers
Answer:
∠A = 60゚
Step-by-step explanation:
Given :-
AB=6√3
perpendicular from point A on BC at E of length 9
EC=3√3
To find :-
Find angle A
Proof :-
In △AEB,
AE = 9
AB = 6√3. [GIVEN ]
Let's Find BE,
Since we know that AE is perpendicular.
So , by pythagorus theorem,
(AB)² = (AE)² + (EB)²
(6√3)² = (9)² + (EB)²
(36 × 3) = 81 + (EB)²
108 = 81 + (EB)²
108 - 81 = (EB)²
27 = (EB)²
√27 = EB
3√3 = EB
BC = BE + CE
BC = 3√3 + 3√3
BC = 6√3
Similarly let's find AC,
In △AEC,
Since we know that AE is perpendicular.
Since we know that AE is perpendicular.So , by pythagorus theorem,
(AC)² = (AE)² + (EC)²
(AC)² = (9)² + (3√3)²
(AC)² = 81 + 27
(AC)² = 108
(AC)² = 6√3
Now,
In △ABC,
AB = AC = BC = 6√3
SINCE,
All sides of the △ABC are equal,
therefore,
it is an equilateral triangle.
and we know that all angles of an equilateral triangle are 60゚.
hence,
∠A = 60゚