Question

▸

These figures are similar. The perimeter and
area of one are given. The area of the other
is also given. Find its perimeter and round
to the nearest tenth.
Perimeter = 21.3 m
Area = 16 m²
Perimeter [? ]m
Area = 25 m²
Enter

Answer 1

Check the picture below.

bearing in mind that the ratio of the sides of similar figures is the same as the ratio of their perimeters

`\stackrel{\textit{\Large perimeters}}{21.3\hspace{5em}p}\hspace{5em}\stackrel{\textit{\Large areas}}{16\hspace{5em}25} \\\\[-0.35em] ~\dotfill\\\\ \cfrac{(21.3)^2}{(p)^2}~~ = ~~\cfrac{16}{25}\implies \left( \cfrac{21.3}{p} \right)^2=\cfrac{16}{25}\implies \cfrac{21.3}{p}=\sqrt{\cfrac{16}{25}}\implies \cfrac{21.3}{p}=\cfrac{√(16)}{√(25)} \\\\\\ \cfrac{21.3}{p}=\cfrac{4}{5}\implies 106.5=4p\implies \cfrac{106.5}{4}=p\implies {\Large \begin{array}{llll} 26.625=p \end{array}}`