Question

The perimeter of a triangle ABC is 100 cm.The length of AB is 45 cm and the length of BC is 32 cm.What is the length ofCA?

Answer 1

Recall that the perimeter of the triangle ABC is given by the following formula:

$Perimeter=AB+BC+CA\text{.}$

Substituting the given data we get:

$100\operatorname{cm}=45\operatorname{cm}+32\operatorname{cm}+CA\text{.}$

Solving the above equation for CA we get:

$\begin{gathered} CA=100\operatorname{cm}-45\operatorname{cm}-32\operatorname{cm} \\ =23\operatorname{cm}\text{.} \end{gathered}$

Answer: The length of CA is 23cm.