In the right-angled triangle ABC, the height CD is drawn to the hypotenuse AB; K is the middle of BC.
In the right-angled triangle ABC, the height CD is drawn to the hypotenuse AB; K is the middle of BC. Find AD and KD if the angle ABC = 60 degrees, AB = 8 cm.
Through the length of the hypotenuse AB and the angle ABC, we determine the length of the leg BC.
Cos60 = CB / AB.
CB = AB * Cos60 = 8 * 1/2 = 4 cm.
According to the condition, point K is the middle of the leg BC, then CK = BK = BC / 2 = 4/2 = 2 cm.
Since СD is the height of the triangle, then the BCD triangle is rectangular, and DK is its median, then, by the property of the median, the length is DK = СK = BK = 2 cm.
In the triangle ВDК DК = ВK, and the angle DВК = 60, then the triangle DВK is equilateral, ВD = ВK = DК = 2 cm.
Then AD = AB – BD = 8 – 2 = 6 cm.
Answer: The length of the segment AD is 6 cm, KD is 2 cm.