Angle A in parallelogram ABCD = 30 degrees, the bisector of angle A intersects side BC at point E
Angle A in parallelogram ABCD = 30 degrees, the bisector of angle A intersects side BC at point E so BE = 4 and EC = 2. Find the area of this parallelogram
Since AE is the bisector of angle A, the angle BAE = DAE.
Angle DАЕ = BEA as cross-lying angles at the intersection of parallel lines AD and BC secant AE. Then the angle BAE = BEA, and the triangle ABE is isosceles and AB = EB = 4 cm.
Since in a parallelogram the opposite sides are equal, then AD = BC = BE + CE = 4 + 2 = 6 cm.
Let’s draw the height of the VN of the parallelepiped. Then, in a right-angled triangle ABN, the VN leg lies opposite the angle 30, and therefore is equal to half the length of the hypotenuse AB. VN = AB / 2 = 4/2 = 2 cm.
Determine the area of the parallelogram.
S = AD * BH = 6 * 2 = 12 cm2.
Answer: The area is 12 cm2.