Q5 of 31 Page 110

A triangle is to be drawn with one side 8 centimetres and an angle on it 40°. What is the minimum length of the side opposite this angle?

We know that perpendicular length drawn between two lines is the smallest length.


Let AB = 8 cm and ∠ BAX = 40°



From B draw perpendicular on AX say BC.


In Δ ABC,


BC = AB × sin 40°


(From table, sin 40° = 0.64)


⇒ BC = 8 × 0.64 cm


⇒ BC = 5.12 cm


The minimum length of the side opposite to angle 40° is 5.12 cm.


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