Question : In $\triangle$ABC, $\angle$A = $\angle$B = 60°, AC = $\sqrt{13}$ cm, the lines AD and BD intersect at D with $\angle$D = 90°. If DB = 2 cm, then the length of AD is:
Option 1: 3 cm
Option 2: 3.5 cm
Option 3: 4 cm
Option 4: 4.7 cm
New: SSC CHSL tier 1 answer key 2024 out | SSC CHSL 2024 Notification PDF
Recommended: How to crack SSC CHSL | SSC CHSL exam guide
Don't Miss: Month-wise Current Affairs | Upcoming government exams
Correct Answer: 3 cm
Solution :
$\angle$C = 180° – 60° – 60° = 60°
So, it is an equilateral triangle.
$\therefore$ AB = BC = AC = $\sqrt{13}$ cm
In $\triangle$ADB,
AB
2
= AD
2
+ DB
2
⇒ AD = $\sqrt{(\sqrt{13})^2-2^2}=\sqrt{9}=3$ cm
Hence, the correct answer is 3 cm.
Related Questions
Know More about
Staff Selection Commission Combined High ...
Result | Eligibility | Application | Admit Card | Answer Key | Preparation Tips | Cutoff
Get Updates BrochureYour Staff Selection Commission Combined Higher Secondary Level Exam brochure has been successfully mailed to your registered email id “”.