Lesson 2

  Area of a triangle

  The area of the square in the diagram is .

The square can be divided into 2 equal triangles by drawing a diagonal ( that's a line joining two opposite corners ). The area of each of the triangles is half of the area of the square or .

It can be helpful to label the lines on the diagram.

   h = height                           

The  angle between the height and  the base is a  right angle. (90°) 

The area of a triangle can also be found by multiplying the height (h) by the base (b) and dividing by 2.

Area of a triangle:   Area = b × ^h /₂   

  Area of a triangle:       

        Area of a triangle:    

or the base times the height divided by 2.

       To find the area of the  rectangle containing the triangle, multiply the base length by the height:  

Practice these methods and then try Quiz 2 on Area. Remember to use the Checklist to keep track of your work.