SECONDES EURO - TRIANGLES
DEFINITION OF A TRIANGLE: it is a three-sided polygon that can be classified by angles, as in an acute triangle, or by sides, as in an equilateral triangle.
- sum of interior angles =180°
- area : (basis*height)/2
1. TRIANGLE TYPES CLASSIFIED BY ANGLES.
RIGHT –ANGLED TRIANGLE OR RIGHT TRIANGLE (US): it is a triangle with one of its angle exactly equal to 90°.
OBTUSE TRIANGLE: it is a triangle with one of its angle greater than (>) 90°.
ACUTE TRIANGLE: it is a triangle with all three angles less than (<) 90°.
2. TRIANGLE TYPES CLASSIFIED BY SIDES
EQUILATERAL TRIANGLE: it is a triangle that has equal length on all three sides. All equilateral triangles are equiangular triangles.
ISOSCELES TRIANGLE: it is a triangle with two equal length sides. It has also has two equal angles (two congruent angles and sides).
SCALENE TRIANGLE: It is a triangle with all no equal side and no equal angles too.