Isosceles trapezoidal question, what is isosceles trapezoid

1. Angle DBC = 30°

2. The upper bottom is 8 long and the lower bottom is 12

3. The root number 3 with a circumference of 10 and an area of 3 times

Definition of isosceles trapezoid:

1. One set of quadrilaterals with parallel (unequal) opposite sides and another set of quadrilaterals with unparallel but equal opposite sides.

2. Isosceles trapezoidal is a plane figure, which is a special trapezoid. The two inner angles of the isosceles trapezoidal on the same base are equal; The isosceles trapezoidal shape has equal waists, parallel bases, equal diagonals, and complementary diagonals.

Properties of isosceles trapezoid:

1. The two inner angles on the same bottom of the isosceles trapezoid are equal.

2. The two waists are equal, the two bottoms are parallel, and the diagonals are equal.

3. The length of the median line of the isosceles trapezoid is half of the sum of the length of the upper and lower bottom edges.

4. Two trapezoids with equal inner angles on the same bottom are isosceles trapezoids.

5. The two waists are equal, the two bottoms are parallel, the two bottom angles are equal, the diagonals are equal, and they are connected to the circle.

Two trapezoids with equal waists are called isosceles trapezoids, and they are called isosceles trapezoids.

The formula for the area of an isosceles trapezoid: the area of the trapezoid = (upper bottom + lower bottom) * height 2, with a, b, h respectively to represent the upper bottom, lower bottom and height of the trapezoid, s represents the area of the trapezoid, then s=(a+b)h 2.

One group of opposites are equal and not parallel, another set of quadrilaterals with parallel opposites is an isosceles trapezoid, two trapezoids with equal angles on the same base are isosceles trapezoids, trapezoids with equal diagonal lines are isosceles trapezoids, and trapezoids with two equal waists are isosceles trapezoids.

An isosceles trapezoid is a set of quadrilaterals in which the opposite sides are parallel (not equal) and the other is not parallel but equal. An isosceles trapezoidal is a flat figure that is a special trapezoidal shape.

A set of quadrilaterals that are parallel (unequal) to the opposite sides and the other is not parallel but equal to the other is called an isosceles trapezoid. As the name suggests, an isosceles trapezoid is a trapezoid with two equal waists, and it is a special case of trapezoid. The following decision can be used as a theorem:

1. One group of opposites are equal and not parallel, and the other group of quadrilaterals with parallel opposites is an isosceles trapezoid.

2. A trapezoid with two equal angles on the same bottom is an isosceles trapezoid.

3. A trapezoid with equal diagonal lines is an isosceles trapezoid.

4. A trapezoid with equal waists is an isosceles trapezoid.

The following decisions are not used as theorems:

1. A quadrilateral with equal diagonals and two isosceles triangles is an isosceles trapezoid.

2. The diagonally complementary trapezoidal is an isosceles trapezoid.

An isosceles trapezoidal is a quadrilateral shape in which the opposite sides are parallel and two of the adjacent sides are of equal length.

Isosceles trapezoids have many characteristics and properties. One of the most striking features is that its two hypotenuses are equal, also known as "isosceles". In addition, because the two base edges of an isosceles trapezoid are parallel, its area can be calculated by adding the length of the upper and lower bases and multiplying it by half the height.

In addition, the sum of the internal angles of an isosceles trapezoid is 360 degrees, while the diagonal length can be calculated according to the Pythagorean theorem.

Isosceles trapezoids have a wide range of applications in geometry, such as in the proof and calculation of plane geometry, isosceles trapezoids are often used to simplify problems and prove conclusions. In real life, the shape of isosceles trapezoids is also very common, such as the treads of stairs, the borders of furniture, etc., which may use isosceles trapezoidal design resistance letter.

The isosceles trapezoidal determination theorem is that two trapezoids with equal internal angles on the bottom edge of the same late posture are isosceles trapezoids. A trapezoid with two equal inner angles on the same bottom edge is an isosceles trapezoid, a trapezoid with two unadjacent sides that are equal to each other is an isosceles trapezoid, and a trapezoid with equal diagonal lines is an isosceles trapezoid.

Judgment method: 1. One group of opposite sides are equal and not parallel, and the other group of quadrilaterals with parallel opposite sides is isosceles trapezoidal.

2. A trapezoid with two equal angles on the same bottom is an isosceles trapezoid.

3. A trapezoid with equal diagonal lines is an isosceles trapezoid.

4. A trapezoid with equal waists is an isosceles trapezoid.

A group of quadrilaterals with opposite sides parallel (not equal) and another group of quadrilaterals with opposite sides that are not parallel but equal are called isosceles trapezoids.

Commonly used guide lines:

1. Shift one waist.

2. Two points above the bottom and two points at the bottom of the bottom to make a perpendicular line.

3. Extend the two waists at one point.

4. Translate a diagonal.

The circumference of an isosceles trapezoid = upper bottom + lower bottom + 2 waist.

The AD and BC edges are parallel and unequal, and the AB and DC edges are not parallel but equal.

Hope it helps!

A quadrilateral shape with two equal waists and a set of opposite sides parallel to each other is called a trapezoid.

A trapezoid with two equal waists is an isosceles trapezoid.

Two trapezoids with equal waists.