These activity sheets will give your students practice in calculating the altitudes of given triangles.

How Is the Altitude of a Triangle Used in Math? When we draw a perpendicular line it serves as the altitude of the triangle that we draw from its vertex to its opposite side. We also call it the height. With altitude, we can make a right angle with the base. Use of Altitude - Mainly, we use the altitude to calculate the triangle's area. For example; Area = ½ base × height. We can easily calculate the base by using height and area. For example; Base = [ (2 × Area) / Height ]. Formulas for Determining the Altitude - This depends entirely on the type of triangle that you are working with. For Equilaterala - Altitude Formula - h = (1/2) × √ 3 × s, For Isosceles - h = √ ( a2 - b2/4 ), For Right - h = √ ( xy ) Problem - Altitude of the equilateral triangle formula: All angles are equal to 60 degrees. ADB has Sin 60 degree = h / AB. We know all sides of the triangles are equal = AB = BC = AC = s (equilateral sides) Therefore, Sin 60 degrees = h /s. √ 3 / 2 = h /s. h = ( √ 3 / 2 ) s.

The altitude is a measure of the height as we have said. This is drawn with a line segment at a right angle from a side to vertex of the opposite corner. Every triangle will therefore have three altitudes. In most cases the altitude is formed inside the shape itself, but is one of the angles is obtuse a line can drawn outside the triangle continuing to point of the adjacent angle (forming a right angle). These worksheets explains how to find the missing points of a shape on a coordinate grid. Your students will use these worksheets to learn how to determine and draw the altitudes of given the figures.

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Altitudes of Triangles Lesson

This worksheet explains how to draw the altitude of a triangle. A sample problem is solved.

Lesson and Practice

This worksheet reviews how to draw one altitude to the base of the triangle. A sample problem is solved, and two practice problems are provided.


Students will draw the altitude of each triangle that they are presented with. Ten descriptions are provided.

Practice Worksheet

Given a series of triangles, students will draw the altitudes. Ten problems are provided.

Worksheet Drill

Students will determine and draw these guys up for each triangles. Eight problems are provided.

Skills Warm Up

Students will draw upon what they have learned in this series. Three problems are provided.