Question

How far up a wall will an 11-meter ladder reach, if the foot of the ladder is 4 meters away from the base of the wall?

A. 11 m
B. 4 m
C. 115
D. 245

Answer 1

• Length of ladder= 11 meter

Distance from foot of ladder to base of wall = 4 meter

Let height of Wall up to which Ladder reach = h meter

By using Pythagorean theorem :

• ⇒(Length of ladder)²=(Height of Wall up to which Ladder reach)² + ( Distance from foot of ladder to base of wall)²

⇒(11)²=(Height of Wall up to which Ladder reach)²+4²

Subtracting 16 from both sides

⇒121 -16 = (Height of Wall up to which Ladder reach)²

⇒105 = (Height of Wall up to which Ladder reach)²

⇒ Height of Wall up to which Ladder reach