วิธีการคำนวณ Inscribed Circle
learn.whatIsHeading
The inscribed circle (incircle) is the largest circle that fits inside a triangle, tangent to all three sides. Its radius (inradius) equals the triangle area divided by the semi-perimeter.
สูตร
r = A/s where A = area, s = semi-perimeter
- r
- inradius (inscribed circle radius) (length)
- A
- triangle area (length²)
- s
- semi-perimeter (length)
คำแนะนำทีละขั้นตอน
- 1r = Area / s
- 2Where s = (a+b+c)/2 (semi-perimeter)
- 3Area found via Heron's formula
- 4Centre is at the intersection of the angle bisectors (incentre)
ตัวอย่างที่มีคำตอบ
อินพุต
Triangle 3, 4, 5
ผลลัพธ์
r = 6/6 = 1
อินพุต
Triangle 5, 12, 13
ผลลัพธ์
r = 30/15 = 2
คำถามที่พบบ่อย
What is the incentre of a triangle?
The incentre is the center of the inscribed circle, located at the intersection of the three angle bisectors.
Is the inradius always smaller than the circumradius?
Yes, for any triangle, the inradius r is always less than the circumradius R.
How many inscribed circles can a triangle have?
Exactly one. The inscribed circle is unique and is the largest circle that fits inside the triangle.
พร้อมที่จะคำนวณแล้วหรือยัง? ลองใช้เครื่องคิดเลข Inscribed Circle ฟรี
ลองด้วยตัวคุณเอง→