HOW TO DRAW ELLIPSE

Question 6 - Ellipses & Parabolas

Main Parts of an Ellipse Major Axis (the long one) Minor Axis (the short one) Focal Points Vertex

Key Concepts

The distance from a focal point to the end of the minor axis is equal to 1/2 the major axis

The distance from a focal point to any point on the curve of an ellipse and back to the other focal point is equal in length to the major axis

---

How to Draw an Ellipse - Circle Method

1 - Draw a circle with a diameter equal to the major axis and a circle with a diameter equal to the minor axis using the same centre 2 - Divide the circles into 12 slices using your 30 deg set square 3 - Draw a vertical line down from each point where the lines meet the outer circle and draw a horizontal line across where the lines meet the smaller circle. Mark out the points where the horizontal and vertical lines meet. 4 - Use these points to freehand sketch the ellipse

---

How to Draw a Tangent to an Ellipse at a Point, p 1 - Locate the 2 focal points, F1 & F2 2 - Draw a line from each focal point to P and extend them outside the ellipse 3 - Bisect the angle between the focal point lines as shown in blue 4 - The tangent is the line that bisects the angle at P