Question

The lengths of two sides of a triangle are $12$ cm and $15$ cm. Between what two measures should the length of the third side fall?

• A. $3and27$
• B. $5and20$
• C. $10and12$
• D. $8and12$

Answer 1

The correct option is A $3and27$

A triangle ABC has $3$ sides and they have to satisfy the following.

$|a-b|<c<(a+b)$

The length of a side must be less the sum of the other two and more than the difference between the other two.

Hence, the third side has to be more than $(15-12)=3$ cm. Also it has to be less than $(15+12)=27$ cm.

It is in between $3cmand27$ cm.