Types and Properties of Angles Straight Angles Angles which measure exactly 180° (degrees) are straight angles. Therefore, straight angles are straight lines. Angles are represented by the sign ϴ, called theta. That is, for straight angles, ϴ= 180°. Right Angles Angles which measure exactly 90° are right angles, that is, ϴ = 90°. Obtuse Angles…

# Tag: geometry

## Types and Properties of Triangles

Types and Properties of Triangles Equilateral Triangles Triangles with all three sides equal in length and all three angles equal in magnitude, are called equilateral triangles. Since the angles in a triangle sum to 180° and the size of each angle is the same in an equilateral triangle, the angles are all 60°. Isosceles Triangles…

## Types and Properties of Quadrilaterals

Types and Properties of Quadrilaterals Quadrilaterals are any four-sided figure, joined by four straight lines, that is, Quadrilaterals are four-sided polygons. Properties of Quadrilaterals: -Four sides. -Four vertices (corners). -Interior angles sum to 360°. -Exterior angles sum to 360°. Things to Know: -Diagonals are line segments that join two opposite vertices (corners). -Two sides are…

## Regular Polygons

Regular Polygons Regular polygons have all sides, and all angles equal. Size of Internal Angles To find the size of the internal angles of a regular polygon with ‘n’ sides, use the formula: For example, the size of the interior angles of the pentagon (five sides) above is: The sum of all the interior angles…

## Pythagoras’ Theorem

Pythagoras’ Theorem Pythagoras’ theorem states that for a right angled triangle, if a square was to be drawn on each side of the triangle, the area of the square on the hypotenuse side (the side opposite the 90° angle), is equal to the sum of the area of the two squares drawn on the other…

## Sine, Cosine and Tangent Ratios

Sine, Cosine and Tangent Ratios Sides of a Right Angled Triangle The order in which the names of the sides are determined is listed below: -The longest side of the triangle is called the Hypotenuse. -The side opposite to the angle under consideration, in this case A, is called the Opposite. -The remaining side is…