Back to homeMathematics · Precalculus · Change subject
Start for free
Notes

Exercises: Notable lines and points of a triangle

Practice★☆☆
Calculate the coordinates of the centroid of the triangle whose vertices are $A(1, 2)$, $B(3, -4)$ and $C(-1, 5)$.

Calculate the coordinates of the centroid of the triangle whose vertices are $A(1, 2)$, $B(3, -4)$ and $C(-1, 5)$.

Solve
Practice★☆☆
Find the explicit equation of the median starting from the vertex $A$ in the triangle with vertices $A(0, 0)$, $B(4, -2)$ and $C(2, 6)$.

Find the explicit equation of the median starting from the vertex $A$ in the triangle with vertices $A(0, 0)$, $B(4, -2)$ and $C(2, 6)$.

Solve
Practice★☆☆
Determine the general equation of the altitude drawn from the vertex $B$ in the triangle with vertices $A(-2, 1)$, $B(4, 3)$ and $C(1, -5)$.

Determine the general equation of the altitude drawn from the vertex $B$ in the triangle with vertices $A(-2, 1)$, $B(4, 3)$ and $C(1, -5)$.

Solve
Practice★☆☆
Calculate the general equation of the perpendicular bisector of the side $AB$ of a triangle knowing that its corresponding vertices are $A(2, 5)$ and $B(-4, 1)$.

Calculate the general equation of the perpendicular bisector of the side $AB$ of a triangle knowing that its corresponding vertices are $A(2, 5)$ and $B(-4, 1)$.

Solve
Practice★☆☆
Find the coordinates of the orthocenter of the right triangle with vertices $A(0, 0)$, $B(6, 0)$ and $C(0, 4)$.

Find the coordinates of the orthocenter of the right triangle with vertices $A(0, 0)$, $B(6, 0)$ and $C(0, 4)$.

Solve
Practice★☆☆
Calculate the coordinates of the circumcenter of the triangle with vertices $A(0, 0)$, $B(8, 0)$ and $C(0, 6)$.

Calculate the coordinates of the circumcenter of the triangle with vertices $A(0, 0)$, $B(8, 0)$ and $C(0, 6)$.

Solve
Practice★☆☆
Check analytically if the point $P(1, 2)$ is the centroid of the triangle with vertices $A(2, 3)$, $B(-1, 4)$ and $C(5, 1)$.

Check analytically if the point $P(1, 2)$ is the centroid of the triangle with vertices $A(2, 3)$, $B(-1, 4)$ and $C(5, 1)$.

Solve
Practice★☆☆
Calculate the equations of the two angle bisectors of the angles formed by the lines containing the sides of a triangle, whose equations are $3x-4y+1=0$ and $4x+3y-5=0$.

Calculate the equations of the two angle bisectors of the angles formed by the lines containing the sides of a triangle, whose equations are $3x-4y+1=0$ and $4x+3y-5=0$.

Solve
Practice★★☆
Three trees in an agricultural plantation are located at the points $A(1, 1)$, $B(5, 3)$ and $C(1, 5)$ (coordinates expressed in tens of feet). A sprinkler is to be…

Three trees in an agricultural plantation are located at the points $A(1, 1)$, $B(5, 3)$ and $C(1, 5)$ (coordinates expressed in tens of feet). A sprinkler is to be installed that is equidistant from the three trees. Calculate the coordinates of the point where it should be placed (circumcenter) and the water range radius necessary to water them.

X Y A B C O
Solve
Practice★★☆
Three telecommunications antennas form a triangle with vertices at $A(-4, 0)$, $B(2, -2)$ and $C(5, 5)$. Calculate the location of the center of gravity (centroid) to…

Three telecommunications antennas form a triangle with vertices at $A(-4, 0)$, $B(2, -2)$ and $C(5, 5)$. Calculate the location of the center of gravity (centroid) to place a central transmitter, and determine the exact distance from this transmitter to the antenna $C$.

Solve
Practice★★☆
In a triangle with vertices $A(1, 2)$, $B(3, 4)$ and $C(a, b)$, it is known that the centroid is the point $G(2, 1)$. Calculate the coordinates of the vertex $C$ and the…

In a triangle with vertices $A(1, 2)$, $B(3, 4)$ and $C(a, b)$, it is known that the centroid is the point $G(2, 1)$. Calculate the coordinates of the vertex $C$ and the Cartesian equation of the median starting from this vertex.

Solve
Practice★★☆
A building has a triangular floor plan with vertices at the points $A(-1, -1)$, $B(5, -1)$ and $C(2, 5)$. Calculate the coordinates of the orthocenter of this triangle.

A building has a triangular floor plan with vertices at the points $A(-1, -1)$, $B(5, -1)$ and $C(2, 5)$. Calculate the coordinates of the orthocenter of this triangle.

Solve
Practice★★☆
The orthocenter of a triangle is the point $H(2, 2)$. Two of its vertices are known, which are $A(-1, 3)$ and $B(4, 1)$. Calculate the coordinates of the vertex $C$.

The orthocenter of a triangle is the point $H(2, 2)$. Two of its vertices are known, which are $A(-1, 3)$ and $B(4, 1)$. Calculate the coordinates of the vertex $C$.

Solve
Practice★★☆
Given the triangle with vertices $A(0, 0)$, $B(4, 0)$ and $C(2, 6)$, find the coordinates of its centroid and its orthocenter. Next, obtain the general equation of the…

Given the triangle with vertices $A(0, 0)$, $B(4, 0)$ and $C(2, 6)$, find the coordinates of its centroid and its orthocenter. Next, obtain the general equation of the Euler line that passes through both points.

Solve
Practice★★☆
A triangle has vertices $A(1, 1)$ and $B(5, 1)$. The vertex $C$ lies on the line of equation $y = x+2$. Knowing that the triangle is isosceles and that the unequal side…

A triangle has vertices $A(1, 1)$ and $B(5, 1)$. The vertex $C$ lies on the line of equation $y = x+2$. Knowing that the triangle is isosceles and that the unequal side is $AB$, find the coordinates of the vertex $C$ and of its circumcenter.

Solve
Practice★★☆
Three mountain shelters are located at the coordinates $A(0, 4)$, $B(4, 0)$ and $C(-2, -2)$ (expressed in miles). A rescue helicopter hovers at the circumcenter of the…

Three mountain shelters are located at the coordinates $A(0, 4)$, $B(4, 0)$ and $C(-2, -2)$ (expressed in miles). A rescue helicopter hovers at the circumcenter of the triangle formed by the shelters. Calculate the coordinates of the helicopter and the radius of the circle that encompasses the three shelters.

Solve
Practice★★★
Given a generic right triangle whose vertices are located at $A(0,0)$, $B(a,0)$ and $C(0,b)$ with $a, b > 0$, prove analytically that its orthocenter coincides with the…

Given a generic right triangle whose vertices are located at $A(0,0)$, $B(a,0)$ and $C(0,b)$ with $a, b > 0$, prove analytically that its orthocenter coincides with the origin and its circumcenter is exactly the midpoint of the hypotenuse.

Solve
Practice★★★
The vertices of a triangle are $A(1, 0)$, $B(3, 0)$ and $C(t, 2t)$, where $t$ is a real parameter that determines the position of the vertex $C$ on a line. Find the…

The vertices of a triangle are $A(1, 0)$, $B(3, 0)$ and $C(t, 2t)$, where $t$ is a real parameter that determines the position of the vertex $C$ on a line. Find the equation of the locus described by the centroid of the triangle as $t$ varies.

X Y C(t, 2t) Locus of centroid A B C G
Solve
Practice★★★
Given a triangle $ABC$, the vertex $A(1, 3)$ and the equations of two of its medians are known: $x-2y+1=0$ and $y-1=0$. Calculate the coordinates of the vertices $B$ and…

Given a triangle $ABC$, the vertex $A(1, 3)$ and the equations of two of its medians are known: $x-2y+1=0$ and $y-1=0$. Calculate the coordinates of the vertices $B$ and $C$.

Solve
Practice★★★
Given the vertices of a triangle $A(-2, -1)$, $B(4, -1)$ and $C(1, 5)$, find the coordinates of the orthocenter $H$, the centroid $G$ and the circumcenter $O$. Prove…

Given the vertices of a triangle $A(-2, -1)$, $B(4, -1)$ and $C(1, 5)$, find the coordinates of the orthocenter $H$, the centroid $G$ and the circumcenter $O$. Prove analytically that the distance between the orthocenter and the centroid is twice the distance between the centroid and the circumcenter ($HG = 2GO$).

Solve
Practice★★★
Three roads cross forming a triangle delimited by the lines $x=0$, $y=0$ and $3x+4y-12=0$. Calculate the coordinates of the incenter to place a roundabout tangent to the…

Three roads cross forming a triangle delimited by the lines $x=0$, $y=0$ and $3x+4y-12=0$. Calculate the coordinates of the incenter to place a roundabout tangent to the three roads, and the radius of this roundabout.

X Y I 3x+4y-12=0
Solve
Practice★★★
In a triangle $ABC$, the vertex $A$ has coordinates $(-1, 2)$. The altitudes drawn from the vertices $B$ and $C$ are contained in the lines of equations $x-y+1=0$ and…

In a triangle $ABC$, the vertex $A$ has coordinates $(-1, 2)$. The altitudes drawn from the vertices $B$ and $C$ are contained in the lines of equations $x-y+1=0$ and $2x+y-4=0$ respectively. Determine the coordinates of the vertices $B$ and $C$.

Solve
Practice★★★
The vertex $A(2, 5)$ of a triangle $ABC$ is known. The perpendicular bisectors of the sides $AB$ and $AC$ have the equations $x-y+2=0$ and $2x+y-3=0$, respectively. Find…

The vertex $A(2, 5)$ of a triangle $ABC$ is known. The perpendicular bisectors of the sides $AB$ and $AC$ have the equations $x-y+2=0$ and $2x+y-3=0$, respectively. Find the coordinates of the vertices $B$ and $C$.

Solve
Practice★★★
Find the coordinates of the vertices $B$ and $C$ of a triangle knowing that the vertex $A$ is $(3, 1)$, its circumcenter is the point $O(5, 2)$ and its centroid is…

Find the coordinates of the vertices $B$ and $C$ of a triangle knowing that the vertex $A$ is $(3, 1)$, its circumcenter is the point $O(5, 2)$ and its centroid is $G(4, 2)$.

Solve