An isosceles triangle is made of three zinc rods. Will there be any change in its base angles with the rise in temperature? Give reasons for your answer.

Explanation

Let the initial length of each equal arm of the triangle be `alpha` and the length of the base be b. Hence, initial ratio of the lengths of the arms `=a:a:b.`
Let the rise in temperature be t and the coefficient of linear expansion of zinc be `alpha.`
Now, the ratio of the lengths of the arms
`" "=a(1+alphat):a(1+alphat):b(1+alphat)=a:a:b.`
Hence, the ration of the lengths of the sides remains unchanged with the rise in temperature. Thus, the base angles too, do not change.