4. Draw an obtuse-angled ∆LMN. Draw its altitudes and denote the orthocenter by ‘O’.

Step 1: Start by drawing an obtuse triangle ∆LMN. An obtuse triangle is a triangle in which one of the angles is an obtuse angle (greater than 90 degrees).

Step 2: Draw the altitudes of the triangle. An altitude of a triangle is a line segment drawn from one vertex of the triangle perpendicular to the opposite side.

Step 3: The point where all three altitudes intersect is called the orthocenter. Mark this point as 'O'.

Please note that in an obtuse triangle, the orthocenter lies outside the triangle.

Step 1: Start by drawing an obtuse triangle. Label the vertices as L, M, and N. Make sure one of the angles is greater than 90 degrees to ensure it's an obtuse triangle.

Step 2: Draw the altitude from each vertex. The altitude is a line drawn from a vertex perpendicular to the opposite side.

Step 3: The point where all three altitudes intersect is the orthocenter of the triangle. Label this point as 'O'.

Please note that in an obtuse triangle, the orthocenter will lie outside the triangle.