ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

Area of a semicircle. Finding the area of semi circles.

Updated on March 1, 2013

Area of a semicircle video

To find the area of a semicircle first you need to find the area of the whole circle and divide your answer by 2, as a semicircle takes up half the space of a circle.

To find the area of the circle use A=π×r2.  (A stands for the area of the circle, π is Pi and r is the radius of the circle).

Let’s take a look at an example.

Example 1

Find the area of this semicircle.

Answer

First find the area of the whole circle. Make sure that you use the radius of the circle (the distance halfway across the circle), this is 4 cm as the diameter is 8 cm (the distance all the way across the centre of the circle).

A = π×r2

A= π×42

A= 50.3... cm2

Now all you need to do is divide the answer by 2

50.3... ÷ 2 = 25.1 cm2 (1 d.p)

Example 2

A semicircular shaped doormat has a radius of 7cm. Calculate the area of the doormat.

Answer

To begin with first find the area of the circle by using A = π×r2.

A = π×r2

A= π×72

A= 154.1... cm2

Again, all you need to do now is to divide the area of the circle by 2.

Do this by 154.1 ÷ 2 = 77.1 cm2 (1 d.p)

Extra Tips

If you don’t have a scientific calculator then use Pi as 3.14 on your pocket calculator.

As you do more examples you might just want to use the formula A = π×r2/2. This will means less lines of working out.


Comments

Submit a Comment

  • profile image

    Yomama 5 years ago

    thanks broham

  • profile image

    travis 5 years ago

    thank you so much, it helped me with my homework

  • profile image

    andrea 5 years ago

    Thank this really helped me on my math homework

  • profile image

    Palm 6 years ago

    Lovely jubbly thanks a bunch

  • profile image

    Mikah 6 years ago

    I still don't understand this I am only 10 but my teacher has said that this is a question that is going to appear in my exam I don't understand what all the tt things mean sorry

  • profile image

    Amana 6 years ago

    THANKS SO MUCH NOW I CAN ANWSER THE QUESTION ON MY MATH TEST TOMORROW! EVERYBODY SAID IT WAS HARD!!!!!!!!! BUT ILL PRON=BABLY DO GOOD NOW !!!! THANKS A BUNCH!

  • profile image

    Daniel 6 years ago

    fantastic that is absolutly nice thanks

  • profile image

    Chubby cuteness 6 years ago

    Really good thank you so much I am so grateful

  • profile image

    Rizza 6 years ago

    Thanks Very easy to understand. Awesome

  • profile image

    Johnson 7 years ago

    Nice

    I Like it

    Guess what

    Geometry is also cool

    Even my dog understands this

    Really helpful thnx!

    See ya

  • profile image

    dd 7 years ago

    thanx you really helped me ace my test

  • profile image

    shaz 7 years ago

    fantastic very useful thanks.

  • profile image

    Soph 7 years ago

    Thanks, this really helped me answer a question in an exam paper :)

  • profile image

    (: 7 years ago

    thank you, this really does help :D

  • catman3000 profile image
    Author

    Mark 7 years ago from England, UK

    Thanks for your nice comments.

  • profile image

    maths teacher  8 years ago

    this is very useful thants

  • profile image

    :) 8 years ago

    Thanks, ;) simple and easy to understand as always, just hope it comes up in my exam =(

  • profile image

    koyasha bridges 8 years ago

    thank you so much

  • profile image

    marco  8 years ago

    thx this was helpful as my mate gave me the wrong note i would of failed if it weren't for this website i love u moderator :P

  • profile image

    niv 8 years ago

    this was really simple and easy to understand, thanks

working

This website uses cookies

As a user in the EEA, your approval is needed on a few things. To provide a better website experience, hubpages.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: "https://hubpages.com/privacy-policy#gdpr"

Show Details
Necessary
HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
LoginThis is necessary to sign in to the HubPages Service.
Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
AkismetThis is used to detect comment spam. (Privacy Policy)
HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
Features
Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
MavenThis supports the Maven widget and search functionality. (Privacy Policy)
Marketing
Google AdSenseThis is an ad network. (Privacy Policy)
Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
Index ExchangeThis is an ad network. (Privacy Policy)
SovrnThis is an ad network. (Privacy Policy)
Facebook AdsThis is an ad network. (Privacy Policy)
Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
AppNexusThis is an ad network. (Privacy Policy)
OpenxThis is an ad network. (Privacy Policy)
Rubicon ProjectThis is an ad network. (Privacy Policy)
TripleLiftThis is an ad network. (Privacy Policy)
Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
Statistics
Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)