A tetrahedron has four equilateral triangles as sides
true apex :)
Four triangles, similar to the large one, but one third the size.
Four.
Fuor toothpicks from 16 leave 12 which, by coincidence (?) is exactly enough for four equilateral triangles!
No, he did not. In actual fact nobody "invented" congruency.
law of congruency
Triangles are congruent when:All three sides are the same length (SSS congruency)Two sides and the angle between them are the same length (SAS congruency)Two angles and the side between them are the same length (ASA congruency)
triangle congruency
Search Definition of Congruency
You have acute, right, and obtuse triangles when referring to the measure of the largest angle, and you have equilateral, isosceles, and scalene triangles when referring to the congruency of the triangle's sides.
Because triangles add up to 180 degrees
A s a, s s s, a a a, a a s, & s a s
RHS congruency, or, right angle, hypotenuse and corresponding side.
These are all congruency tests for triangles. S=side A=angle R=right angle H=hypotenuse Take one of the tests for example. AAS If two angles and one side is the same between two triangles, then the triangles are congruent. A link is provided to the Wikipedia article on congruence. It's really easy to read and understand. And it has drawings, too. (ASA was not included in the list, but it is covered in the Wikipedia post with the other forms.)
Side Side Side Side Angle Side Angle Side Side Angle Side Angle Side Side Angle Angle Angle Side With Angle congruency and Side congruency in that order
From ancient times, properties of quadrilaterals have been used especially in art, design and architecture. Diagonal of a rectangle divides it into two congruent triangles and the idea of congruency especially in triangles had been used by Egyptians to build The Great Pyramids of Giza!!!!! The idea of congruency of triangles initially from diagonal of quadrilaterals also helped Leonardo Da Vinci to paint the world famous 'Monalisa'!!!!! So, what other wonders do you want from quadrilaterals????!!!????