परिमिती
त्रिकोणाची परिमिती = तिन्ही बाजूंच्या लांबींची बेरीज

सूत्रे 

टीप : वर्तुळाच्या परिमितीला परीघ म्हणतात.

लंबवर्तुळाची परिमिती

a = मोठी त्रिज्या; b = छोटी त्रिज्या.

Approximation 1 :

This approximation is within about 5% of the true value, so long as `a' is not more than 3 times longer than `'`b' (in other words, the ellipse is not too "squashed"):

ellipse perimeter (approx) = 2pi into square root of [(a squared+b squared)/2].

उदा० a = १०; b = ६. तर परिमिती = ५१.८१२४७३३७.(approximate).

Approximation 2 :

ellipse perimeter (approx) = pi into [ 3(a+b) - square root of ((3a+b)(a+3b))]

उदा० a = १०; b = ६. तर परिमिती = ५१.०५३९७२७९.(approximate).

The famous Indian mathematician Ramanujan came up with this better approximation :

Approximation 3 :

रामानुजमचे सूत्र : First we calculate "h":

h = (a-b)2/(a+b)2  

Then, ellipse perimeter (approx) = pi(a+b)(1 + 3h/(10+square root of (4-3h))

उदा० a = १०; b = ६. तर परिमिती = ५१.०५३९९७७३ (Most accurate)

भूमिती