Properties Of Triangles Ques 2

If in a $\triangle P Q R, \sin P, \sin Q, \sin R$ are in $AP$, then

(a) the altitudes are in $AP$

(b) the altitudes are in $HP$

(c) the medians are in $GP$

(d) the medians are in $AP$

(1998, 2M)

Show Answer

Answer:

Correct Answer: 2.(b)

Solution:

Formula:

Sine Rule:

  1. By the law of sine rule,

$ \frac{a}{\sin P}=\frac{b}{\sin Q}=\frac{c}{\sin R}=k $

Also,

$ \frac{1}{2} a p _1=\Delta $

$ \begin{array}{ll} \Rightarrow & \frac{2 \Delta}{a}=p _1 \\ \Rightarrow & p _1=\frac{2 \Delta}{k \sin P} \end{array} $

Similarly, $\quad p _2=\frac{2 \Delta}{k \sin Q}$ and $p _3=\frac{2 \Delta}{k \sin R}$

Since, $\sin P, \sin Q$ and $\sin R$ are in AP, hence $p _1, p _2, p _3$ are in HP.



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