Shapes Rectangle Square Circle Triangle Rhombus Squircle Oval Hexagon Pentagon Trapezoid Kite Parallelogram Quadrilateral Polygon Nonagon Heptagon Decagon Octagon Ellipse Parallelepiped Tetrahedron Cylinder Prism Sphere Pyramid Frustum Polyhedron Dodecagon Dodecahedron Octahedron Torus Cube Cone Hyperbola Rectangular Prism Fibonacci Sequence Golden Ratio Parabola Rectangular Prism Fibonacci Sequence Calculators Fraction Calculator Mixed Fraction Calculator Greatest Common Factor Calulator Decimal to Fraction Calculator Fraction Calculator Mixed Fraction Calculator Greatest Common Factor Calulator Decimal to Fraction Calculator Arithmetic Whole Numbers Rational Numbers Place Value Irrational Numbers Natural Numbers Binary Operation Numerator and Denominator Decimal Order of Operations (PEMDAS) Scientific Notation Symmetry Fractions Triangular Number Complex Number Binary Number System Logarithm Binomial Theorem Quartic Function Mathematical Induction Group Theory Modular Arithmetic Euler’s Number Inequalities Sets De Morgan’s Laws Transcendental Numbers Rational Numbers Irrational Numbers Natural Numbers Binary Operation Numerator and Denominator Order of Operations (PEMDAS) Scientific Notation Triangular Number Binary Number System Binomial Theorem Quartic Function Mathematical Induction Modular Arithmetic De Morgan’s Laws Transcendental Numbers Table of Contents Last modified on May 13th, 2024 chapter outline In geometry, a triangle is a plane figure that is enclosed by three line segments. The sum of all the angles of a triangle is equal to 180° The sum of the lengths of any two sides of a triangle is greater than the length of the third side The difference between any two sides of a triangle is less than the length of the third side An exterior angle of a triangle is equal to the sum of its interior opposite angles. This is called the exterior angle property of the triangle Area of a Triangle It is the total space enclosed by the triangle. The formula is given below: Problem: Finding the area of a triangle when the BASE and HEIGHT are known Find the area of a triangle whose base is 6 cm and height is 4 cm? As we know, A = ½ ( b × h ) = ½ (6 × 4) cm = 12 cm 2 Problem: Finding the area of a triangle when only SIDES are known Find the area of a triangle whose three sides are 3 cm, 4 cm, and 5 cm. Here we will use the Heron’s formula, A = √ s ( s – a )( s – b )( s – c ) , where s = ½ ( a + b + c ) In this triangle, s = ½ (3 cm + 4 cm+ 5 cm) = 6 cm Since, A = √ s ( s – a )( s – b )( s – c ) = √6(6-3)(6-4)(6-5) = √36 = 6 cm 2 Perimeter of a Triangle It is the distance covered around the edges of a triangle or simply the length of the boundary covered. The formula is given below: Find the perimeter of a triangle whose three sides are 4 cm, 6 cm, and 8 cm As we know, P = a + b + c , where a, b, c are the measure of three sides = 4 cm + 6 cm + 8 cm = 18 cm Triangles are classified into two groups: based on sides , 1) scalene , 2) isosceles , and 3) equilateral triangles ; based on angles , 1) acute angle , 2) obtuse angle , and 3) right or right-angled triangles . The differences between the types are given below: Apart from the above three types, there is Equiangular Triangle with all three internal angles equal to 60° and, thus having all sides equal, similar to an Equilateral Triangle Triangle Worksheets Congruent Triangles Worksheets Special Right Triangles Worksheets Special Triangles Worksheets Similar Triangles Worksheets Area of a Triangle Worksheets Area of Triangles and Parallelograms Worksheets Area of Triangles and Trapezoids Worksheets Area and Perimeter of Triangles Worksheets Angles in a Triangle Worksheets Classifying Triangles Worksheets Isosceles and Equilateral Triangles Worksheets Right Triangle Worksheets Right Triangle Trigonometry Worksheets Triangle Sum Theorem Worksheets Midsegment of a Triangle Worksheets Triangle Inequality Theorem Worksheets Special Segments in Triangles Worksheets Triangle Proportionality Theorem Worksheets Centers of Triangles Worksheets Constructing Triangles Worksheets Congruent Triangles Worksheets Special Right Triangles Worksheets

Special Triangles Worksheets Similar Triangles Worksheets Area of a Triangle Worksheets Area of Triangles and Parallelograms Worksheets Area of Triangles and Trapezoids Worksheets Area and Perimeter of Triangles Worksheets Angles in a Triangle Worksheets Classifying Triangles Worksheets Isosceles and Equilateral Triangles Worksheets Right Triangle Worksheets Right Triangle Trigonometry Worksheets Triangle Sum Theorem Worksheets Midsegment of a Triangle Worksheets Triangle Inequality Theorem Worksheets Special Segments in Triangles Worksheets Triangle Proportionality Theorem Worksheets Centers of Triangles Worksheets Constructing Triangles Worksheets Further Reading Scalene Triangle Isosceles Triangle Equilateral Triangle Acute angled Triangle Obtuse angled Triangle Right triangle Triangle Special Right Triangles Congruent Triangles Altitude of a Triangle Similar Triangles Median of a Triangle Triangle Inequality Theorem Centroid of a Triangle Triangle Sum Theorem Incenter of a Triangle Vertices of a Triangle Hypotenuse of a Triangle Isosceles Triangle Theorem Exterior Angle of a Triangle Midsegment of a Triangle Base of a Triangle Perpendicular Bisector of a Triangle Angle Bisector of a Triangle Scalene Triangle Isosceles Triangle Equilateral Triangle Acute angled Triangle Obtuse angled Triangle Right triangle Triangle Special Right Triangles Congruent Triangles Altitude of a Triangle Similar Triangles Median of a Triangle Triangle Inequality Theorem Centroid of a Triangle Triangle Sum Theorem Incenter of a Triangle Vertices of a Triangle Hypotenuse of a Triangle Isosceles Triangle Theorem Exterior Angle of a Triangle Midsegment of a Triangle Base of a Triangle Perpendicular Bisector of a Triangle Angle Bisector of a Triangle Last modified on May 13th, 2024 One thought on “ Triangle ” It’s a very good website for maths students and even other practices Reply It’s a very good website for maths students and even other practices Leave a comment Cancel reply Related Materials Area of a Triangle Worksheets Triangle Worksheets Related Materials Join Our Newsletter © 2026 Mathmonks.com . All rights reserved. Reproduction in whole or in part without permission is prohibited.