The vertices of a triangle ABC are A(1, 2), B(–3, 4), C(5, 8), then orthocentre of △ABC is
Correct Answer :
(3/2, 1)
Solution :
The correct option is (3/2, 1).
Step-by-step Explanation:
The orthocentre of a triangle is the point of intersection of its altitudes. As shown in the provided diagram, we have a triangle with vertices:
We will find the equations of two altitudes, (altitude from vertex to side ) and (altitude from vertex to side ), and solve them to find their intersection point, which is the orthocentre .
Step 1: Find the equation of altitude
First, find the slope of side using the slope formula:
Since the altitude is perpendicular to , its slope () is the negative reciprocal of :
Using the point-slope form, the equation of the line representing altitude passing through is:
Simplifying this equation:
— (Equation 1)
Step 2: Find the equation of altitude
Next, find the slope of side :
Since the altitude is perpendicular to , its slope () is the negative reciprocal of :
Using the point-slope form, the equation of the line representing altitude passing through is:
Simplifying this equation:
— (Equation 2)
Step 3: Solve the linear equations to find the orthocentre
We have the following system of linear equations:
1)
2)
Subtract Equation 1 from Equation 2:
Substitute back into Equation 1:
Thus, the intersection point of the altitudes is the orthocentre .
Access expert-curated educational resources and study materials—completely free.
Create, conduct, and manage professional online assessments with Crey. Perfect for teachers and institutes.
Copyright © 2026 Crey. All Rights Reserved.