15 points! which of the following is not a characteristic of a regular polyhedron? a. it is also considered to be a convex polyhedron. b. the number of edges meeting at each vertex is the same for all vertices. c. all of the faces are congruent. d. it is not a platonic solid.

look a the sides they are perpendicular

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4

“ a line segment that has the endpoints on the circle and passes through the midpoint is called the diameter. the diameter is twice the size of the radius. a line segment that has its endpoints on the circular border but does not pass through the midpoint is called a chord. a circle is the same as 360 small circle up the number 0 . i hope this .

so the rectangle is 80cm (area)

now to find the area of a triangle.

base times height.

4 times 8.

your answer is 96cm.

hope this .