Which pair of triangles must be similar?
A. Triangles 1 and 2 each have a 35° angle.
B. Triangles 3 and 4 are both isosceles. They each have a 40° angle.
C. Triangle 5 has a 30° angle and a 90° angle. Triangle 6 has a 30° angle and a
70° angle.
D. Triangle 7 has a 50° angle and a 25° angle. Triangle 8 has a 50° angle and a
105° angle.

Correct  B. and D.

Explanation:

This question is from mathematics and not from physics.

According to the triangle similarity theorem the two triangles are similar if the two angles of one triangle are congruent with the two angles of the other triangle.

B.

Isosceles triangles as a special case are similar if they have one angle the same and that is an angle of 40°.

D.

Triangle 7 has angles 50°, 25° and 105°

Triangle 8 has angles 50°, 105° and 25°

So they have all three angles congruent and therefore they are similar.

God is with you!!!

u=13

v=30

s/t=u+1\2at

=13+431/2

=13+265.5

=278.5

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia