Question 4
Given ¯¯¯¯¯¯¯¯AB of length 3.9 cm, construct ¯¯¯¯¯¯¯¯PQ such that the length ¯¯¯¯¯¯¯¯PQ is twice that of AB . Verify by measurement.
(Hint: Construct ¯¯¯¯¯¯¯¯¯PX such that length of ¯¯¯¯¯¯¯¯¯PX = length of ¯¯¯¯¯¯¯¯AB;
then cut off ¯¯¯¯¯¯¯¯¯XQ such that ¯¯¯¯¯¯¯¯¯XQ also has the length of ¯¯¯¯¯¯¯¯AB.)
Steps of construction:
(i) Draw a line 'l'.
(ii) Construct ¯¯¯¯¯¯¯¯¯PX such that length of ¯¯¯¯¯¯¯¯¯PX = length of ¯¯¯¯¯¯¯¯AB
(iii) Then cut of ¯¯¯¯¯¯¯¯¯XQ such that ¯¯¯¯¯¯¯¯¯XQ also has the length of ¯¯¯¯¯¯¯¯AB.
(iv) Thus the length of ¯¯¯¯¯¯¯¯¯PX and the length of ¯¯¯¯¯¯¯¯¯XQ added together make twice the length of ¯¯¯¯¯¯¯¯AB
Verification:
By measurement, we find that PQ = 7.8
= 3.9 cm + 3.9 cm
= ¯¯¯¯¯¯¯¯AB + ¯¯¯¯¯¯¯¯AB = 2 x ¯¯¯¯¯¯¯¯AB