How to find the area of a regular pentagon formula


Asked by admin @ in Mathematics viewed by 294 People


What is the area of regular pentagon with a side of 12 inches? Round the answer to the nearest 10th.

Answered by admin @



The area would be 247.8 sq. in.

We start out finding the length of the apothem.  The apothem of a regular polygon is given by 

A=\frac{s}{2\tan{(\frac{180}{n})}}

where s is the side length and n is the number of sides.  Using our information, we have
A=\frac{5}{2\tan{(\frac{180}{5})}}=\frac{5}{2\tan{36}}=8.26

Now we find the area of the polygon using the formula:
A = n(1/2)(b)(h), where n is the number of sides, b is the side length, and h is the length of the apothem:

A = 5(1/2)(8.26)(12) = 247.8

Similar Questions

Find the area of a regular pentagon of side 8cm

Asked by admin @ in Math viewed by 388 persons

Find the area of a regular pentagon of side 8 cm

What's the formula to find the area of a triangle

Asked by admin @ in Mathematics viewed by 290 persons

Plzzzzz help me!!!!!! Which is the correct formula to find the area of triangle AED?

How do you find the area of a regular decagon

Asked by admin @ in Mathematics viewed by 271 persons

find the area of the regular decagon if the apothem is 5 inches and a side is 3.2 inches. Round to the nearest whole number

How to find the surface area of a regular pyramid

Asked by admin @ in Mathematics viewed by 311 persons

Find the surface area of the regular pyramid. 10 yd 9 yd 7.8 yd lyd?

How to find the surface area of a cone formula

Asked by admin @ in Mathematics viewed by 326 persons

The surface area of a cone is found using the formula SA = Pir2 + Pirl. Describe what each part of the formula represents and how these parts are used …

Find the measure of each angle of a regular pentagon

Asked by admin @ in Math viewed by 316 persons

Find each angle of regular pentagon​

How to find area of z score on ti 84

Asked by admin @ in Mathematics viewed by 295 persons

Find the -scores that bound the middle 96 of the area under the standard normal curve by using the TI-84 calculator.

How do you find the area of a rectangular prism

Asked by admin @ in Mathematics viewed by 298 persons

could you use the formula for the surface area of a rectangular prism to find the surface area of a cube explain please help me.

What is the formula to find the average daily balance

Asked by admin @ in Business viewed by 375 persons

Calculate the average daily balance, finance charge, and new balance using the average daily balance method. The account balance on June 1st is $104.00. On June 19th a payment of …

How do you find a surface area of a prism

Asked by admin @ in Mathematics viewed by 328 persons

How is the process of finding the surface area of a rectangular prism the same as finding the surface area of a triangular prism? How is it different? ANSWER: For …

Find the distance between two points using the distance formula

Asked by admin @ in Mathematics viewed by 336 persons

what are the steps to finding the distance between two points on a coordinate grid using pythagorean theorem

How do you find the surface area of a prism

Asked by admin @ in Mathematics viewed by 308 persons

How is the process of finding the surface area of a rectangular prism the same as finding the surface area of a triangular prism? How is it different? ANSWER: For …

How to find the total surface area of a sphere

Asked by admin @ in Mathematics viewed by 307 persons

Find the total surface area of a sphere with a radius of 9 m​

What is the formula for the area of an octagon

Asked by admin @ in Mathematics viewed by 347 persons

Find the area of a regular octagon with a side length of 10cm

How to find area of square when perimeter is given

Asked by admin @ in Mathematics viewed by 297 persons

A square has a perimeter of 25 inches. What is the area of the square?

Most viewed questions in Mathematics


Unit 6 similar triangles homework 2 similar figures answer key

Asked by maham237 @ in Mathematics viewed by 18354 persons


All things algebra unit 7 polygons and quadrilaterals answer key

Asked by admin @ in Mathematics viewed by 8159 persons


Gina wilson all things algebra 2016 answer key unit 11

Asked by admin @ in Mathematics viewed by 5777 persons



Unit 1 geometry basics homework 4 angle addition postulate answers

Asked by maham237 @ in Mathematics viewed by 3935 persons


Unit 6 exponents and exponential functions homework 8 answer key

Asked by maham237 @ in Mathematics viewed by 3252 persons


The manager of a vacation resort believes that the ages

Asked by maham237 @ in Mathematics viewed by 2924 persons



What is 271 403 rounded to the nearest ten thousand

Asked by maham237 @ in Mathematics viewed by 2792 persons


Unit 1 geometry basics homework 3 angle relationships answer key

Asked by maham237 @ in Mathematics viewed by 2581 persons


Homework 2 parallelograms

Asked by maham237 @ in Mathematics viewed by 2502 persons



Why would a prism beat a sphere in a competition?

Asked by maham237 @ in Mathematics viewed by 2480 persons


John wants to send a letter to peter

Asked by maham237 @ in Mathematics viewed by 2461 persons


An artist sells a painting for 20.50 but uses 5.75

Asked by maham237 @ in Mathematics viewed by 2430 persons



Unit 4 congruent triangles homework 1 classifying triangles answer key

Asked by maham237 @ in Mathematics viewed by 2419 persons


Unit 4 congruent triangles homework 2 angles of triangles

Asked by maham237 @ in Mathematics viewed by 2074 persons


Compare the values of the 2s and 5s in 55220

Asked by maham237 @ in Mathematics viewed by 1794 persons