Maths question

nobodythere

http://www.e-xamit.ie/tutorials/leaving/maths/higher/2002/2/02/a2.html

r is the point where the lines intersect by the way... I don't understand how they got that ratio thing for the first part (using equiangular triangles, or otherwise, find the ratio |or|:|rp|). Any help? Pretty please?

BraveheartGal

wheres r in the diagram??!?

nobodythere

They left it out of the diagram accidentally, it's where op and qa intersect

the smiley one

Basically, as far as I can gather the triangles oqr and arp are congruent (I think thta's the word) basically angles are all the same therefore sides are in proportion. The way they got the ratio was by using the sides oc and ab;
oq is 1/2 of oc (2/4) and ap is 3/4 of ab

The ratios of these corresponding sides are the same as the ratio for the other corresponding side i.e. or and op therefore the same ratio is applicable to these sides.

Gettit? hope I explained it alright...

BraveheartGal

*shakes head in disbelief*

nobodythere

Ah yes, thank you! I couldn't see how the triangles were congruent. Thanks