How to draw with isosceles right triangle ruler and gauge

The following drawing with ruler and gauge has never been mentioned, such as "Ba ⊥ AC" and other rogue practices

Dividing a right triangle into two isosceles triangles

Make the vertical bisector of the hypotenuse, connect its perpendicular foot and right angle vertex

It is known to make right triangles with all corners and hypotenuses Drawing with ruler and gauge Writing is not required

As ∠ man = 90 °
Cut AB on ray am equal to the longer point B of the known right angle side, draw an arc with point B as the center of the circle, take the length of the known oblique side as the radius, and intersect with the ray an at point C. then, ⊿ ABC is the triangle to be made

Drawing with ruler and gauge: as shown in the drawing, make an angle equal to the known angle Known: For:

Known: ∠ AOB,
It can be calculated as: ∠ ECF is equal to ∠ AOB,
As shown in the figure:
The ECF is obtained

In the right triangle ABC, CD is the height on the hypotenuse AB, ∠ B = 60 ° and BD = 3. Find the length of ab

BC=2BD=6
AB=2BC=12

As shown in the figure, in the right triangle ABC, CD is the center line on the hypotenuse AB, and the angle CDB = 130 degrees. Find the degree of angle A and angle B As shown in the picture

The length of the hypotenuse of a triangle is equal to the length of its hypotenuse
So ad = DC = BD
So ∠ a = ∠ DCA, ∠ B = ∠ DCB
Because ∠ CDB = 130 °
So ∠ DBC = ∠ DCB = (1 / 2) (180 ° - ∠ BDC) = 25 °
Because ∠ BDC = ∠ a + ∠ DCA
So ∠ a = ∠ DCA = (1 / 2) ∠ BDC = 65 °
That is, a = 65 ° and B = 25 °

In the right triangle ABC, CD is the center line on the hypotenuse ab. if a = 30 degrees, then the angle BCD=

60 degrees

As shown in the figure, CD is the center line on the hypotenuse ab of RT △ ABC. If CD = 4, then ab=______ .

∵ CD is the center line on the hypotenuse ab of RT △ ABC, CD = 4,
∴AB=2CD=8．

Known: as shown in the figure, in RT △ ABC, EF is the median line, CD is the hypotenuse, and CD is the midline on the hypotenuse ab. it is proved that EF = CD

EF=1/2AB
CD=1/2AB
So CD = EF

As shown in the figure, in RT △ ABC, EF is the median line and the median line on the oblique edge ab of CD. It is proved that EF = CD Why? Because EF is the median line and CD is the center line on the hypotenuse ab So: CD = 1 / 2Ab

prove:
∵ EF is the median line [known]
ν EF = half AB [the median line of the triangle is equal to half of the bottom edge]
∵ the center line on the hypotenuse ab of CD [known]
ν CD = half of the hypotenuse of a right triangle
ν EF = CD [equivalent substitution]

How to draw with isosceles right triangle ruler and gauge