In a right-angled triangle ABC, the hypotenuse AB is 8 cm. The external angle at the apex A is 150 degrees, find the leg BC.

Given: ABC-right triangle
Hypotenuse AB = 8 cm, external kgol at apex A is 150 degrees
Find: leg BC?
Decision :
180-150 = 30 degrees angle A (since the sum of the outer angle and the angle of the triangle is 180 degrees)
Opposite an angle of 30 degrees lies a side equal to half the hypotenuse
BC = 8: 2 = 4 cm
Answer: BC = 4cm