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 it’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 .