Area of Triangles
The area of a triangle is ½ the area of a rectangle. A = ½ x length x width A = ½ lw A = lw/2 To find the area of a triangle, you can multiply the length and width then divide by 2. OR…You can solve ½ x length x width.
LENGTH is the same a BASE. WIDTH is the same as HEIGHT. See below… WIDTH HEIGHT LENGTH BASE
LENGTH is the same a BASE. WIDTH is the same as HEIGHT. See below… WIDTH HEIGHT LENGTH BASE A TRIANGLE’S BASE IS TYPICALLY THE BOTTOM PART OF A TRIANGLE WHILE THE HEIGHT IS ALWAYS THE STARTS AT THE HIGHEST POINT FROM THE BASE, STRAIGHT DOWN. THE TWO LINES ALWAYS CREATE A RIGHT ANGLE.
So, area of a triangle is ½ x base x height. A = ½ bh or bh/2
Sometimes the base line and the height line are not clearly identified because the given triangle is not a right triangle. When this is the case, identify any line as a base and draw and imaginary height line. The imaginary height line, also called the altitude, creates a right angle with the base line.
This visual shows HOW a triangle has an area ½ of that of the rectangle, with the same base and height.
Here is another example… Area of the rectangle = 18 units2 The triangle = 9 units2