In an isosceles trapezoid, the bases are 5 and 23 at the base angle is 45 ° find the area of the trapezoid.

Let us draw the ВН height from the top of the obtuse angle of the trapezoid.

Since the AВСD trapezoid is isosceles, the ВН height cuts off two segments based on the AD, the length of the smaller of which is equal to the half-difference of the lengths of the trapezoid bases.

AH = (AD – BC) / 2 = (23 – 5) / 2 = 18/2 = 9 cm.

In a right-angled triangle ABН, the angle ВAН = 45, then the angle ABН = 180 – 90 – 45 = 45, and therefore the triangle ABН is isosceles, ВН = AH = 9 cm.

Determine the area of the trapezoid.

Savsd = (ВС + AD) * ВН / = (5 + 23) * 9/2 = 126 cm2.

Answer: The area of the trapezoid is 126 cm2.



One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.