Chapter 5 Angles and Trigonometry

A quadrilateral is a polygon which has 4 vertices and 4 sides enclosing 4 angles and the sum of all the angles is 360°. While the angle sum property of a triangle theorem states that the sum of all three internal angles of a triangle is 180°. In this section, we learn about Angle Properties of Triangles and Quadrilaterals, parallel lines, alternating angles, corresponding angles, quadrilateral angles sum, triangle angle sum, angles sum.

The sum of the interior angles of a polygon = (n - 2) x 180°, where n is the number of sides. In this section, we learn about angle sum of a polygon, angles in a regular polygon.

The sum of the exterior angles of a polygon is 〖360〗^°. In this section, we learn about polygon, exterior angles in polygon, regular polygon.

A hypotenuse is the longest side of a right-angled triangle. Pythagoras theorem states that, in a right-angled triangle, the square of the hypotenuse side is equal to the sum of squares of the other two sides. In this section, we learn about Pythagoras theorem, Pythagoras, converse of Pythagoras theorem, hypotenuse, tangent properties.

A hypotenuse is the longest side of a right-angled triangle. Pythagoras theorem states that, in a right-angled triangle, the square of the hypotenuse side is equal to the sum of squares of the other two sides. In this section, we learn about Pythagoras theorem, Pythagoras, shorter side.

The side opposite to the right angle is called the hypotenuse. The side opposite to the angle θ is called the opposite. The side next to the angle θ is called the adjacent. In this section, we learn about trigonometry, find side, calculating sides.

The angle of elevation is the angle measured upwards from the horizontal. The angle of depression is the angle measured downwards from the horizontal. In this section, we learn about trigonometry, angle of depression, calculating sides, calculating angles.