Answer:
![\Large \boxed{\mathrm{square: 15 \ meters}} \\\\ \Large \boxed{\mathrm{triangle: 20 \ meters}}](https://img.qammunity.org/2021/formulas/mathematics/college/gal4wy0hstwvf86r919dvzs8jpq6fuoz16.png)
Explanation:
The perimeter of a square is
, where s is the side length.
The perimeter of an equilateral triangle is
, where a is the side length.
The side length of the equilateral triangle is 5 more than the side length of the square.
![\sf a = s+5](https://img.qammunity.org/2021/formulas/mathematics/college/dgthg822vr3cjlq14n036r9bzfr6cpyo2c.png)
The perimeter of the square and equilateral triangle are equal.
![\sf 4s=3(s+5)](https://img.qammunity.org/2021/formulas/mathematics/college/s57xrbz6b6zebstztsj4r0zww15wne4wmw.png)
Expanding brackets.
![\sf 4s=3s+15](https://img.qammunity.org/2021/formulas/mathematics/college/1f9stnqriy8y5mn1tcautuagp8w4hap09v.png)
Subtracting 3s from both sides.
![\sf s=15](https://img.qammunity.org/2021/formulas/mathematics/college/8jkqgbqpjpv82ee6u0ezqlsavsj8nnzuge.png)
The side length of the square is 15 meters.
![\sf a=15+5 \\\\\\ a=20](https://img.qammunity.org/2021/formulas/mathematics/college/azdhv1xh94fptjahfan5kn5vs3aklaiyv5.png)
The side length of the triangle is 20 meters.