Question extracted from RD sharma of class 10th, Chapter no. 4
Chapter name:- Triangles
Exercise :- 4.2
This is very basic and important questions. And has been asked in several times in exams.
In this question we have been given the ΔABC,
In which D and E are points on the sides AB and AC respectively such that DE || BC.
Also it is given that AD = 2.5 cm, BD = 3.0 cm, and AE = 3.75 cm,
Now we have to find the length of AC
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RD sharma, DHANPAT RAI publication
Given:
Length of side AD = 2.5 cm, AE = 3.75 cm and BD = 3 cm
To find : Length of side AC
By using Thales Theorem, we get
AD/BD = AE/CE – equation 1
Now, putting values in equation 1,
We get,
2.5/ 3 = 3.75/ CE
2.5 x CE = 3.75 x 3
CE = 3.75×32.5
CE = 11.252.5
CE = 4.5
Now, AC = 3.75 + 4.5
∴ AC = 8.25 cm.
Therefore, the value of AC is 8.25cm