• Congratulations to the Class of 2024 on your results!
    Let us know how you went here
    Got a question about your uni preferences? Ask us here

short and simple circle geo question. (1 Viewer)

conics2008

Active Member
Joined
Mar 26, 2008
Messages
1,228
Gender
Male
HSC
2005
The red drawings are what I drew.

I can say with confidence that CD is diameter

PCKA = Cyclic Quad

< b = 90

but still cant to seem to get in KBL and DKL

help please.
 

Iruka

Member
Joined
Jan 25, 2006
Messages
544
Gender
Undisclosed
HSC
N/A
Is L the point of intersection of KP and BD?

If so, then you prove that triangle BKL is similar to triangle KPA, using the fact that PCKA and CBDA are cyclic quadrilaterals.

Angle BKE = angle PKA (vert opp) then you just have to show that

angle KBE = angle APK

so the other angles are equal also.
 

peckerhead

New Member
Joined
Mar 25, 2008
Messages
4
Gender
Male
HSC
N/A
let angle CBA =x
then angle PCA = x (alternate segment, a tangent at C?)
and because CKAP is cyclic
then angle PKA = x

that's all you need: CB and PK are both inclined at same angle to AB (ie x) and are thence parallel.

result follows.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top