Section 1
Area of Triangles
Property
The area of a triangle is one-half the base, , times the height, .
In this Grade 6 lesson from enVision Mathematics Chapter 7, students apply the triangle area formula A = ½bh to find the areas of various triangles, including right triangles and triangles plotted on a coordinate plane. Students practice identifying the base and height, working with mixed units, and reasoning about how to reverse the formula to solve for an unknown base or height.
Section 1
Area of Triangles
The area of a triangle is one-half the base, , times the height, .
Section 2
Identifying the Height of a Triangle
For any triangle with area , the altitude is drawn perpendicular to the base .
In acute triangles, the altitude falls inside the triangle.
In obtuse triangles, the altitude to the longest side falls outside the triangle and must be drawn to the extension of the base.
Expand to review the lesson summary and core properties.
Section 1
Area of Triangles
The area of a triangle is one-half the base, , times the height, .
Section 2
Identifying the Height of a Triangle
For any triangle with area , the altitude is drawn perpendicular to the base .
In acute triangles, the altitude falls inside the triangle.
In obtuse triangles, the altitude to the longest side falls outside the triangle and must be drawn to the extension of the base.