When the foot of a ladder is 1.8 m from a wall the angle formed by the ladder and the ground is 72 degrees therefore how long is the ladder?

Answer 1

1.8 from the bottom of a wall, with a ladder at angle 72 degrees

would be about 5.8 long

cos72 = 1.8/L

L = 1.8/cos72 = 5.8249

Ladder's Length = about 5.8 meters Long

cos72 = the adjacent side (1.8 m) divided by the hypotenuse (the Ladder Length) of a right triangle

it helps to draw a sketch of the ladder forming a right triangle with the wall and ground

cos72 = about .31

1.8/.31 = about 5.8