Question : Let ABC be an equilateral triangle and AD perpendicular to BC, Then AB2 + BC2 + CA2 =?
Option 1: 2AD2
Option 2: 3AD2
Option 3: 4AD2
Option 4: 5AD2
Recommended: How to crack SSC CHSL | SSC CHSL exam guide
Don't Miss: Month-wise Current Affairs | Upcoming government exams
New: Unlock 10% OFF on PTE Academic. Use Code: 'C360SPL10'
Correct Answer: 4AD2
Solution : Here ABC is an equilateral triangle with side length $a$ and AD $\perp$ BC. So, BD = CD = $\frac{a}{2}$ In $\triangle$ABD, AB2 = BD2 + AD2 ⇒ $a^2=(\frac{a}{2})^2+$ AD2 $\therefore$ AD = $\frac{\sqrt3}{2}a$ = $\frac{\sqrt3}{2}$AB = $\frac{\sqrt3}{2}$BC = $\frac{\sqrt3}{2}$AC [$\because$ AB = BC = AC = $a$] ⇒ AB = $\frac{2}{\sqrt3}$ AD, BC = $\frac{2}{\sqrt3}$ AD, and AC = $\frac{2}{\sqrt3}$ AD $\therefore$ AB2 + BC2 + AC2 = AD2 ($\frac{4}{3}+\frac{4}{3}+\frac{4}{3}$) = 4AD2 Hence, the correct answer is 4AD2.
Candidates can download this e-book to give a boost to thier preparation.
Application | Eligibility | Admit Card | Answer Key | Preparation Tips | Result | Cutoff
Question : If $AD, BE$ and $CF$ are medians of $\triangle ABC$, then which of the following statement is correct?
Option 1: $(AD + BE + CF) > (AB + BC + CA)$
Option 2: $(AD + BE + CF) < (AB + BC + CA)$
Option 3: $(AD + BE + CF ) = (AB + BC + CA)$
Option 4: $(AD + BE + CF ) = \sqrt2(AB+BC+CA)$
Question : In $\triangle ABC$, AB = BC = $k$, AC =$\sqrt2k$, then $\triangle ABC$ is a:
Option 1: Isosceles triangle
Option 2: Right-angled triangle
Option 3: Equilateral triangle
Option 4: Right isosceles triangle
Question : In a $\triangle ABC$, the median AD, BE, and CF meet at G, then which of the following is true?
Option 1: 4(AD + BE + CF) > 3(AB + BC + AC)
Option 2: 2(AD + BE + CF) > (AB + BC + AC)
Option 3: 3(AD + BE + CF) > 4(AB + BC + AC)
Option 4: AB + BC + AC > AD + BE + CF
Question : In $\triangle$ABC, BD and CE are perpendicular to AC and AB respectively. If BD = CE, then $\triangle$ABC is:
Option 1: Equilateral
Option 2: Isosceles
Option 3: Right–angled
Option 4: Scalene
Question : If a + b + c = 1, ab + bc + ca = –1, and abc = –1, then what is the value of a3 + b3 + c3?
Option 1: 1
Option 2: 5
Option 3: 3
Option 4: 2
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile