Applications in 2D

Learning Intentions

  • I can apply trigonometry in word problems involving an angle of elevation.
  • I can apply trigonometry to problem solve in word problems involving an angle of depression.

Terminology

  • Direct distance refers to the hypotenuse of the triangle.
  • The ground is usually the adjacent side of the triangle.
  • Any verticle height is usually the opposite side of the triangle.

Example

Ex 6C, Q2

The height of a building is 46 m. The angle of elevation from the street corner to the top of the building is . What is the direct distance from the street corner to the top of the building, to the nearest metre?

  • In this example, you would visualise a triangle with the given information. You can see the information here.
    • This scenario involves the sine trigonometric ratio. In this case, you would use .
    • You can easily substitute the numbers into the ratio.
  • After substituting the given values, you can solve the equation using trigonometry.