What is a Triangle:
A polygon with 3 edges,
3 vertices, 3 angles.
We take 3 points and connect them with 3 sides below denoted as ΔPQR:
Properties of a Triangle:
Sum of the three interior angles = 180°
Sum of the 2 sides > 3rd side
A triangle with vertices (points) P, Q, R:
is denoted as ΔPQR
Area of a Triangle
With base b and height h:
A = 1/2bh
Acute Triangle:
All 3 angles measure less than 90°
Right Triangle:
Has one angle measuring 90° (right)
The other two angles < 90°
Obtuse Triangle:
Has only one angle measuring > 90°
Obtuse angle is opposite the long side
Scalene Triangle
No Sides Are Equal
Isosceles Triangle
2 sides Are Equal
Equilateral Triangle
All 3 sides are equal
How does the Triangles Calculator work?
Free Triangles Calculator - This lesson walks you through the basics of a triangle and shows you triangle types like acute, right, obtuse, scalene, isosceles, equilateral.
What 2 formulas are used for the Triangles Calculator?
Triangle PQR is written as ΔPQR
The sum of the three interior angles of a triangle equals 180°
What 7 concepts are covered in the Triangles Calculator?
- acute triangle
- A triangle for which all interior angles are acute.
- equilateral triangle
- A triangle with 3 equal sides
- isosceles triangle
- A triangle with two equal sides and an unequal third side
- obtuse triangle
- A triangle which has an obtuse angle as one of its interior angles.
- right triangle
- triangle in which one angle is a right angle
- scalene triangle
- a triangle with three unequal sides
- triangle
- a flat geometric figure that has three sides and three angles