Question

1. A regular pentagon has side length 12 cm. The perimeter of the pentagon is 60 cm and the area is 247.7 cm2. A second pentagon has side lengths equal to 18 cm. Find the perimeter of the second pentagon.

2. The ratio of the areas of two similar polygons is 49:36. If the perimeter of the first polygon is 15 cm, what is the perimeter of the second polygon? Round to the nearest hundredth.

Answer 1

I am not sure, but the answer of 1st question is 90.

Answer 2

Explanation:

1) Since both regular pentagons are similar we have sides are proportional

Perimeter of first pentagon =60 cm

One side = 60/5 =12 cm

Ratio of I pentagon side: II=12:18 =2:3

Perimeter ratio = 2:3

2:3 = 60:x

Hence x = 90 cm.

Perimeter of second = 90 cm

2) When areas have ratio 49:36

sides will have ratio as square roots =7:6

Perimeter also ratio 7:6

Hence 7:6= 15:x

x =Perimeter of II pentagon =90/7 = 12.86 cm.