Trapezoidal diagonal, trapezoidal diagonal is where

The topic is a bit of a problem. Landlord, did you find it? Diagonal question of it.

Proof: Because the triangle aen is similar to the abc

So en bc=an ac

And because DNF is similar to DBC

So nf bc=dn db

Because ADN is similar to CBN

So an nc=dn nb so an ac=dn db so en bc=nf bc so en=nf, is the midpoint of ef.

My understanding is so.,I don't know if it's the meaning of the landlord.。。。

If there's a problem with the question, and then take 100 points to show off?! Hehe.

TrapezoidalDiagonalIt is four corners connected by two pairs of diagonals. The trapezoid can be divided into four triangles, where the area ratio of the triangle with the bottom edge is the square ratio of the bottom edge. The two triangles with the two waists as the base are equal in area.

A trapezoid is a quadrilateral with only one set of opposing sides that are parallel to each other.

The two parallel sides are called the bottom edge of the trapezoid, the longer bottom edge is called the lower bottom, the shorter bottom edge is called the upper bottom, and the other two sides are called the waist.

Geometry in Trapezoidal Mathematics:

A trapezoid is a quadrilateral shape with only one set of opposite sides parallel. The two parallel sides are called the bottom edge of the trapezoid, the longer bottom edge is called the lower bottom, and the shorter bottom edge is called the upper bottom.

The other two sides are called the waist, and the vertical line between the two sides is called the trapezoidal height. A trapezoid with a waist perpendicular to the bottom is called a right-angled trapezoid. A trapezoid with two equal waists is called an isosceles trapezoid.

Isosceles trapezoidal is a special trapezoid, which is determined in the same way as isosceles triangle.

The method of determination is similar. Special case, isosceles trapezoid, right-angle trapezoid.

Take a cautious front diagonally.

If the trapezoid is divided into 2 triangles, the trapezoidal area is equal to the area of the two triangles.

The sum of the same. The diagonal is perpendicular to each other, so the bottom of the two halls is equal to the bottom of the triangle, and the sum of the heights is exactly equal to the other diagonal.

So the trapezoidal area of the wide volt = 1 2 4 5 = 10

There is no formula for trapezoidal diagonals.

It is mainly decided by drawing.

If it's a right-angled trapezoid. Straight acres are connected diagonally. It can be calculated by the Pythagorean theorem.

If it is an ordinary trapezoid, it can only be used to dismantle the old with special angles or Yu Xuan's theorem.

Only the diagonal of an isosceles trapezoidal is equal, and if it is not an isosceles trapezoid, it is not equal. 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. In an isosceles trapezoid, the two parallel sides are called the bottom edge of the trapezoid, the longer bottom edge is called the lower bottom, and the shorter bottom edge is called the upper bottom.

The other two sides are called the waist, and the perpendicular line between the two bases is called the trapezoidal height.

The nature of the isosceles trapezoidal is the same as that of the judgment type or1.The property theorem of isosceles trapezoid: the two angles of an isosceles trapezoidal shape are equal to the bottom of the same annihilator.

2.The two diagonals of an isosceles trapezoid are equal.

3.The isosceles trapezoidal determination theorem is an isosceles trapezoidal with two equal angles on the same base.

4.The trapezoidal shape with equal angular lines on the lease is an isosceles trapezoid.

5.A straight line that passes through the midpoint of the trapezoidal waist and is parallel to the bottom will divide the other waist equally.

6.The median line of the trapezoidal theorem The median line of the trapezoid is parallel to the two bases and is equal to half of the sum of the two bases.

Not evenly divided. A trapezoid is a quadrilateral with only one set of opposite sides parallel. The two parallel sides are called the bottom edge of the trapezoid, the longer bottom edge is called the lower bottom, and the shorter bottom edge is called the upper bottom. In addition, the old beat is called the waist with two leaks; The perpendicular segment sandwiched between the two bases is called trapezoidal height.

A trapezoid with a waist perpendicular to the bottom is called a right-angled trapezoid. A trapezoid with two equal waists is called an isosceles trapezoid.

1. A group of quadrilaterals with parallel sides and another group of quadrilaterals with non-parallel sides is trapezoidal.

2. A group of quadrilaterals with parallel and unequal opposite sides is trapezoidal.

1. Make a high return to envy (determined according to the actual topic);

2. Translate one waist;

3. Translate the diagonal;

4. Reverse extension of the two waists at one point;

5. Take the midpoint of one waist, and connect and extend the two ends of the other waist;

6. Take the midpoint of two bottoms, and make parallel lines of the two waists through the midpoint of one bottom.