We all grow at different rates. Although, the average is about 5'4 or 5'5. Around that you should be okay. That is wrong that is very tall average is from 4ft 9 to 4ft 11

An equilateral triangle has all side of the same length and angle are the same as well. An isoscles triangle has only two sides and two angles that match. i.g. Side(A) 4ft Side(B) 8ft Side(C) 4ft ------Isoscles Side(A) 4ft Side(B) 4ft Side(C) 4ft ------Equilateral

if you have a base line of say 10FT then all you have to do is go to your stop point and count back say 3FT then go back to you stop point and go up 4FT then all you have to do is make your 5FT mark from the 3FT to the 4FT and then you should have a right angle...