Question

The lengths of the sides of a triangle are 4,6, and 7. If the length of the longest side of a similar triangle is 21, find the perimeter of the larger triangle.

Answer 1

$\begin{gathered} P1=4+6+7=17 \\ P2=\text{?} \end{gathered}$

the longest side of P1=7

the longest side of P2=21

$\begin{gathered} \frac{7}{17}=\frac{21}{P2} \\ 7P2=17\cdot21 \\ P2=\frac{357}{7} \\ P2=51 \end{gathered}$

the perimeter of the larger triangle is 51