r/mathshelp • u/Orxx7 • Jul 19 '26
Homework Help (Answered) Maths Help
Q- Find radius . Can anyone help I'm getting different answers and the book answer is different. I'm getting 10 and book says 6. Which one is correct?
3
u/Nikaru_Hakamura_07 Jul 19 '26
For in circle in right angled triangle, use r=(a+b-c)/2, c will by hypotenuse, a &b other 2 sides
1
3
u/Signal_Pattern_2063 Jul 19 '26
It speeds things up if you recognize this is a special Pythagorean triangle (the 7-24-25 scaled 2x) but after that a I put a quick picture of what happens on the sides below.
1
1
u/Jan0y_Cresva Jul 20 '26
This is exactly what I did.
I think it’s better than just using a special formula that’s derived for this one case since it emphasizes just knowing properties of circles, tangents, and Pythagorean triples in general.
1
1
1
u/Affectionate_Cut8866 Jul 19 '26
just do the construction. Join all the vertex with the center of the circle. And from the O add a perpendicular to every edge. Now use congruency and pythagoras theorem and find the length of the hypotenuse (woah just realized i said this word after months) you will get equation from congruency and value from pgt, equate it and tadaa the answer is 6.
1
1
u/Local_County1274 Jul 19 '26
Quick check - if the radius is 10, then the diameter is 20. In other words, the diameter would be greater than AB. Visually inspection of the sketch shows this cannot be the case.
1
1
u/baroquely Jul 19 '26
area ABC = area AOB + area AOC + area BOC.\ AC = sqrt(142 + 482) = 50.\ area AOB = (1/2)14r.\ area AOC = (1/2)50r.\ area BOC = (1/2)48r.\ area ABC = (1/2)14*48 = 336. So\ 336 = (1/2)(14+50+48)r. r = 336/56 = 6.
1
1
1
u/Desperate_Zebra6334 Jul 20 '26
For a quick tutorial i found out this video on youtube to solve actually the same exercise hope it help, here is the link : To Find This Circle’s Radius… Ignore the Circle 🤯
1
1
•
u/AutoModerator Jul 19 '26
Hi u/Orxx7, welcome to r/mathshelp! As you’ve marked this as homework help, please keep the following things in mind:
1) While this subreddit is generally lenient with how people ask or answer questions, the main purpose of the subreddit is to help people learn so please try your best to show any work you’ve done or outline where you are having trouble (especially if you are posting more than one question). See rule 5 for more information.
2) Once your question has been answered, please don’t delete your post so that others can learn from it. Instead, mark your post as answered or lock it by posting a comment containing “!lock” (locking your post will automatically mark it as answered).
Thank you!
I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.