Calculate the Lengths of the Sides and the Area of Triangle ABC
1.1 Calculate the Lengths of the Sides
Use the distance formula to calculate the lengths of the sides:
Length of AB = sqrt((x2 - x1)^2 + (y2 - y1)^2)
For AB:
AB = sqrt((8 - 2)^2 + (7 - 3)^2) = sqrt(36 + 16) = sqrt(52) approximately 7.21
For BC:
BC = sqrt((5 - 8)^2 + (11 - 7)^2) = sqrt(9 + 16) = sqrt(25) = 5
For CA:
CA = sqrt((5 - 2)^2 + (11 - 3)^2) = sqrt(9 + 64) = sqrt(73) approximately 8.54
1.2 Calculate the Area Using the Determinant Method
The area can be calculated using the determinant method:
Area = (1/2) * |x1(y2 - y3) + x2(y3 - y1) + x3(y1 - y2)|
Substitute the coordinates A(2, 3), B(8, 7), C(5, 11):
Area = (1/2) * |2(7 - 11) + 8(11 - 3) + 5(3 - 7)| = (1/2) * 36 = 18
1.3 Calculate the Area Using Heron's Formula
First, calculate the semi-perimeter s:
s = (AB + BC + CA) / 2 = (7.21 + 5 + 8.54) / 2 approximately 10.375
Then, use Heron’s formula:
Area = sqrt(s * (s - AB) * (s - BC) * (s - CA))
Substitute the values to calculate the area.
2. Equation of the Perpendicular Bisectors and Circumcenter
2.1 Find the Perpendicular Bisectors
For each side AB, BC, CA, find the midpoint and the slope of the line segment. The slope of the perpendicular bisector is the negative reciprocal of the original slope.
Midpoints:
- Midpoint of AB: ( (2+8)/2 , (3+7)/2 ) = (5, 5)
- Midpoint of BC: ( (8+5)/2 , (7+11)/2 ) = (6.5, 9)
- Midpoint of CA: ( (2+5)/2 , (3+11)/2 ) = (3.5, 7)
Slopes:
- Slope of AB: (7-3) / (8-2) = 4/6 = 2/3
- Slope of perpendicular bisector: -3/2
Use the point-slope form to find the equation of the perpendicular bisector:
y - y1 = m(x - x1)
Repeat for other sides.
2.2 Find the Circumcenter
Solve the system of equations of the perpendicular bisectors to find the circumcenter.
3. Radius of Circumcircle and Plot
3.1 Radius of the Circumcircle
Use the circumcenter coordinates and any vertex (e.g., A) to calculate the radius:
Radius = sqrt((xcircumcenter - xA)^2 + (ycircumcenter - yA)^2)
3.2 Plot in Excel
- Plot the triangle using the vertices.
- Plot the circumcenter and draw the circumcircle using the radius calculated.
4. Centroid and Orthocenter
4.1 Find the Centroid
Centroid G is the average of the vertices’ coordinates:
G( (x1 + x2 + x3)/3 , (y1 + y2 + y3)/3 )
4.2 Find the Orthocenter
Use the altitudes of the triangle, find the equations, and solve them to get the orthocenter.
5. Type of Triangle
5.1 Use Dot Product to Find Angles
Calculate the angles using the dot product formula:
cos(theta) = (AB dot BC) / (|AB| * |BC|)
5.2 Use Law of Cosines
Use the law of cosines to confirm the angles and classify the triangle.
6. Explore the Circumcenter Path
6.1 Move C Along Line y = x + 6
Track how the circumcenter changes by adjusting the coordinates of C and calculate the circumcenter coordinates each time.
6.2 Plot the Path
Create a plot in Excel showing the movement of the circumcenter as C moves along the line y = x + 6.
Sorry for inconvenience i can`t make an excel and plot
Steps to Create the Excel File and Plot:
1. Calculate the Lengths of the Sides
- Open Excel and create a new worksheet.
- Enter the coordinates of points A(2,3), B(8,7), and C(5,11) in columns A, B, and C.
- A B C
- 1 x_A x_B x_C
- 2 2 8
