relation between arc, radius and central angle. Proof of the trigonometrical ratios of complementary angles

Relation between arc radius and angle     Arc length   =   [radius • central angle (radians)] Arc length   =   circumference • [central angle (degrees) ÷ 360]     Proof of the trigonometric ratios of complementary allied angles Two acute angles are complementary to each other if their sum is equal to 90°. In a right … Read more

area of triangle, condition of co-linearity of three points. Trigonometry – Measure of angles in the sexagesimal. contesimal and circular systems

Area of triangle The area of triangles can be found by using the following formula:   Area =  Base × height / 2 The red line represents the length of the base (call it b if you want) and the blue line represents the length of the height. To get the area, just multiply the value … Read more