trigonometry question

Question

A ladder leans against a wall with its foot 1.5 metres from the wall making for an angle of 45º36' with the ground. How long is the ladder?

Answer 1

The ladder, wall and ground will form a right triangle, with a base 1.5 m and then angle between the hypotenuse and base 45^º 36^′. 

 

The cosine of the angle will equal the length of the base over the hypotenuse.

 

cos(45^° 36^’) = 1.5/H.

 

solve for H.

Answer 2

1.  Draw the picture, showing wall, ladder, ground, and the acute angle.

2.  Label appropriately.

3.  Apply basic trigonometry:  cos (acute angle) = 1.5/L  where L is the ladder length.

4.  Solve!