A regular pentagon has an apothem measuring 20 cm and a perimeter of 145.3 cm. What is the area?

Hi,

The pentagon could be seen as a multiple of 5 triangles, they are exactly the same.

Area of a triangle is apothem x the lenght of the pentagon side / 2.

The area of the whole pentagon is apothem x 5 times the lenght of the pentagon side / 2 = apothem x perimeter / 2 = 20 cm x 145,3 cm / 2 = 1,453 cm².

Easy, huh? : - ))).

Green eyes.