SOLUTION: pthagoras theroem and percentages a paineter was asked to paint a very high wall. he extended his ladder to 13m and placed it 5 metres away from the base of the wall. if he decid

Algebra ->  Rate-of-work-word-problems -> SOLUTION: pthagoras theroem and percentages a paineter was asked to paint a very high wall. he extended his ladder to 13m and placed it 5 metres away from the base of the wall. if he decid      Log On


   

Question 850049: pthagoras theroem and percentages
a paineter was asked to paint a very high wall. he extended his ladder to 13m and placed it 5 metres away from the base of the wall. if he decided to paint from the top of the wall down calculate the following

a) how high up is the ladder placed?
b) after painting the top 5 metres of the wall, the painter steps down to contract part of the ladder. by how many metres does he need to pack his ladder to be able to reach 5 metres lower than the top of the wall?
c) calculate the percentage of the contracted ladder size over the original ladder size.
Answer by josgarithmetic(39616) About Me  (Show Source):
You can put this solution on YOUR website!
Question a) is reasonable, but question b) is not reasonable without knowing more, maybe friction information. We also must be given how high IS the wall.


(a) You are calculating how high up the wall the ladder touches.
y%5E2%2B5%5E2=13%5E2
y=sqrt%2813%5E2-5%5E2%29
highlight%28y=12%29.

(b) We now know how high up the wall the ladder reached in part (a), but we are given no information about the actual height of the wall. "After painting the top 5 meters...", is meaningless. Was the wall 12 meters high? Should the ladder now be adjusted so it would touch 7 meters up the wall? If this were the case, then one assumption which may be possible is to keep all sides of the triangle describing the three points in proportion.