How to make a 40 degree angle with a pair of triangular rulers

This is an impossible problem in mathematics

Can a pair of mathematical trigonometric rulers make a 40 degree angle? It's better to have a few degrees and several degrees

30,45,60,90,75 (30 + 45), 105 (30 + 75), 120 (30 + 90), 135 (45 + 90), 150 (60 + 90), 15 (45-30), 165 (60 + 105) can not spell 40

An angle of 125 ° can be made with a pair of triangular rulers___ (judge right and wrong)

The degrees of the angles in a pair of trigonometric rulers are 30 degrees, 45 degrees, 60 degrees and 90 degrees respectively;
45 ° + 90 ° = 135 ° so the angle of 125 ° can not be obtained by assembling;
So the answer is: ×

The angles that can be made with a pair of triangular plates are______ .

A set of triangular plates can directly obtain four angles of 30 °, 45 °, 60 ° and 90 °,
By addition and subtraction, we can get 15 degrees, 75 degrees, 105 degrees, 120 degrees, 135 degrees, 150 degrees, 180 degrees
So the answer is: 30 degrees, 45 degrees, 60 degrees, 90 degrees, 15 degrees, 75 degrees, 105 degrees, 120 degrees, 135 degrees, 150 degrees, 180 degrees

Can a pair of trigonometric rulers make 30 degree angles

sure

Use a pair of triangles to make angles of 75 degrees, 120 degrees, 15 degrees. Try it

60°+45°=105°
180 ° - 105 ° = 75 degrees
90°+30°=120°
60°-45°=15°

A set of triangular plates cannot draw 75 ° 135 ° 160 ° 105 ° Which degree?

One hundred and sixty

Here are the degrees of the 10 angles. The angles that can be drawn with a set of triangular plates are () 15 / 20 / 35 / 40 / 50 / 55 / 75 / 105 / 115 / 135

45-30=15
45+30=75
60+45=105
90+45=135

If the waist length of an isosceles triangle is known to be 2, and the base is 3, then the area of the isosceles triangle is A. 3 / 2 38 B4 3 / 39 Three parts of C2 Three parts of D4

Go over the top and make it high
It can be seen from the theorem that: height = root (waist ^ 2 - (1 / 2 * bottom edge) ^ 2)
=Radical (39) / 2
S = 1 / 2 * radical (39) / 2 * 3
=3 pieces (39) / 4

The area of an isosceles triangle is 2, the waist length AB is the root 5, and the base angle is α to find the value of Tan α

If the vertex angle is B, then cos B = 3 / 5, Tan B = 4 / 3, and 2 α = 180 degrees - B, then Tan 2 α = (180 degrees - b) = - Tan B = - (4 / 3), from the angle formula, Tan α = 2 or - (1 / 2), because 0 ﹤ 2 α ﹤ 180 ﹤ 180 ﹤ 0 ﹤ 2 α

How to make a 40 degree angle with a pair of triangular rulers