Two circles with radii a and b respectively touch each other externally. Let c be the radius of a circle that touches these two circles as well as a common tangent to these two circles . Then *_*. (No figure given)

(A) 1 upon root a - 1 upon root b = 1 upon root c (B) 1 upon root a + 1 upon root b + 1 upon root c = 0 (C) 1 upon root a + 1 upon root b = 1 upon root c (D) none of these

The answer is C but how?

No vote yet

1 vote

×

Problem Loading...

Note Loading...

Set Loading...

Easy Math Editor

`*italics*`

or`_italics_`

italics`**bold**`

or`__bold__`

boldNote: you must add a full line of space before and after lists for them to show up correctlyparagraph 1

paragraph 2

`[example link](https://brilliant.org)`

`> This is a quote`

Remember to wrap math in \( ... \) or \[ ... \] to ensure proper formatting.`2 \times 3`

`2^{34}`

`a_{i-1}`

`\frac{2}{3}`

`\sqrt{2}`

`\sum_{i=1}^3`

`\sin \theta`

`\boxed{123}`

## Comments

Sort by:

TopNewestfgnc fh

Log in to reply

fg

Log in to reply

iuy

Log in to reply

jk

Log in to reply

b

Log in to reply

rgdf

Log in to reply

k,mjb

Log in to reply

thnhjmf

Log in to reply

uit

Log in to reply

tyhfgh

Log in to reply

l'j

Log in to reply

ghj,h

Log in to reply

thnfg

Log in to reply

vu6vcerg

Log in to reply

opic35

Log in to reply

sxvfb

Log in to reply

547j

Log in to reply

12aw35

Log in to reply

yjmnth

Log in to reply

dfby

Log in to reply

f4gb

Log in to reply

wfd

Log in to reply

wdfw

Log in to reply

wsw

Log in to reply

muhbb

Log in to reply

efgvds

Log in to reply

dvb

Log in to reply

mn

Log in to reply

mn,kl

Log in to reply

vvbxvb

Log in to reply

hgncb

Log in to reply

vb cvb c

Log in to reply

hjhfn

Log in to reply

ergerfg

Log in to reply

erhrg

Log in to reply

bgth

Log in to reply

qw12

Log in to reply

hdfb

Log in to reply

gnrgn

Log in to reply

fhm

Log in to reply

kukra sing glo

Log in to reply

buj duyungs mohammad kron kar

Log in to reply

abut kayaf shu na ila

Log in to reply

qwer

Log in to reply

22e

Log in to reply

tt

Log in to reply

jhf

Log in to reply

dgyj

Log in to reply

tyi

Log in to reply

hello

Log in to reply

hi

Log in to reply

a

Log in to reply

Hint: Pythagorean's formula. Let the points of contact between the circle and the common tangent be \(T_A, T_B, T_C\). Find \(T_AT_B, T_AT_C, T_CT_B\) in terms of \(a,b,c\). Anyway draw a figure yourself.

Log in to reply