### Area of a Circle Practice #### Question 1

Given a circle with the radius of 5cm. Find the circumference of this circle. Take π as 3.14. A. 78.5 cm
B. 78.5 cm2
C. 31.4 cm2
D. 31.4 cm

### Step by Step Solution

• #### Step 1

The picture below shows the circle with the radius of 5cm. d. • #### Step 2

To calculate the area, we can start with the formula for the area of a circle: • #### Step 3

Since the radius is given as 5cm, we can substitute r with 5. Similarly, we can substitute π with 3.14. After doing so, we can calculate for A, as shown below: • #### Step 4

Now, the calculated number 78.5 only has meaning if we include the unit for it. Since the radius is in cm, the unit for the area will be cm2. Hence:

A = 78.5 cm2
•
{"ft_lang_label":"__label__en","ft_lang_prob":0.90370333,"math_prob":0.9785375,"size":690,"snap":"2020-10-2020-16","text_gpt3_token_len":179,"char_repetition_ratio":0.14577259,"word_repetition_ratio":0.03076923,"special_character_ratio":0.25507247,"punctuation_ratio":0.1595092,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.998602,"pos_list":[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20],"im_url_duplicate_count":[null,null,null,null,null,null,null,4,null,null,null,2,null,null,null,4,null,null,null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2020-02-17T07:32:53Z\",\"WARC-Record-ID\":\"<urn:uuid:76898278-b722-4d50-9719-9f872e73bb94>\",\"Content-Length\":\"35800\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:9b43a41d-cd29-4fdc-a2f8-0fb057a249f1>\",\"WARC-Concurrent-To\":\"<urn:uuid:35f11b46-91aa-4bda-8054-7166af674e35>\",\"WARC-IP-Address\":\"173.247.219.12\",\"WARC-Target-URI\":\"https://www.mathexpression.com/circle-practice.html\",\"WARC-Payload-Digest\":\"sha1:KVHQPWSNEM74AK6DDK3HYY3I453GSJY2\",\"WARC-Block-Digest\":\"sha1:3B7PTY6XYUH7SOTQUDEXZOTHWYN2SHRT\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2020/CC-MAIN-2020-10/CC-MAIN-2020-10_segments_1581875141749.3_warc_CC-MAIN-20200217055517-20200217085517-00326.warc.gz\"}"}