Parabola Rectangle Method
Parabola Method of Tangent

**PROBLEM 1** : A BALL THROWN IN AIR ATTAINS 100 M HIEGHT
AND COVERS HORIZONTAL DISTANCE 150 M ON GROUND.
Draw the path of the ball (projectile)

**Construction**

**Step 1.** Draw rectangle of above size and
divide it in two equal vertical parts

**Step 2.** Consider left part for construction.
Divide height and length in equal
number of parts and name those
1,2,3,4,5& 6

**Step 3.** Join vertical 1,2,3,4,5 & 6 to the
top center of rectangle

**Step 4.** Similarly draw upward vertical
lines from horizontal1,2,3,4,5
And wherever these lines intersect
previously drawn inclined lines in
sequence Mark those points and
further join in smooth possible curve.

**Step 5.** Repeat the construction on right side
rectangle also.Join all in sequence.
This locus is **Parabola** .

**Problem 2** :
Draw an isosceles triangle of 100 mm long base and
110 mm long altitude. Inscribe a parabola in it by method of tangents.

**Construction**

**Step 1**. Construct triangle as per the given
dimensions.

**Step 2.** Divide itâ€™s both sides in to same no.of equal parts.

**Step 3.** Name the parts in ascending and descending manner, as shown.

**Step 4.** Join 1-1, 2-2,3-3 and so on.

**Step 5.** Draw the curve as shown i.e. tangent to all these lines. The above all lines being
tangents to the curve, it is called **method of tangents** .