5. In the given figure, A ABC - A ADE. If
AE : EC = 4: 7 and DE = 6.6 cm, find BC.
If 'x' be the length of the perpendicular from
A
D
E
B
С
A to DE, find the length of perpendicular from
A to BC in terms of "x'.
Answers
Answered by
2
Answer:
In triangle ABC, since AB=AD, the angles opposite to the sides will also have the same relation.
=>∠ADB=∠ABD
Now, since sum of angles in a triangle ABC =180
o
∠ABD+∠ABD+20
0
=180
o
=>2∠ABD=160
o
=>∠ABD=80
o
In triangle AEC, since AE=EC, the angles opposite to the sides will also have the same relation.
=>∠EAC=30
0
Now, since sum of angles in a triangle ABC =180
o
∠ABC+∠BAC+30
0
=180
o
∠ABD+∠BAC+30
0
=180
o
80
o
+∠BAC+30
0
=180
o
=>∠BAC=70
o
=>∠BAD+∠DAE+∠EAC=70
o
=>20
0
+∠DAE+30
0
=70
o
=>∠DAE=20
o
.
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