Question

Find the volume using the shaded base. True or False... The height of the pyramid using the 5,12,13 base is 2.4 cm

Answer 1

If the shaded are is the base. Height is 3 cm. As you see the side with 3 cm length is perpendicular to side with 4 cm length which is a side of the shaded base. So height is 3 cm.

Answer 2

seems to be 2 questions there

Answer 3

though the shaded area is not the 5,12,13 triangular face

Answer 4

@zarax I guess what they mean is
right now the triangular face of 5, 12,13 is facing UP, if we put it facing DOWN, so it becomes the base of the pyramid, then the height of that POSITION, will be the "altitude" up to the vertex above of 90 degrees

Answer 5

then again, I dunno what the shaded area role is in the whole thing heheh

Answer 6

im sorry the second question, the true false one is the one i need help with i said false but i dont know how to justify that answer or even if its right.

Answer 7

well, @peoplesay1214 what's the volume for a pyramid?

Answer 8

the volume is 24 cm^3

Answer 9

well, I meant ... hmm. I meant equation wise :S

Answer 10

oh for a pyramid .... the formula?

Answer 11

right

Answer 12

so what does that mean

could you find the volume of the pyramid using the shaded area ALONE?

Answer 13

v=1/3ah

Answer 14

I mean, it's so ambiguous

Answer 15

v=1/3(area of base)(height)

Answer 16

yes the shaded area as the base and the height as 3

Answer 17

right, so we know the height, "3", if we knew the "shaded area", that is the BASE, then we could use it in the formula, so I guess you can get the volume with it

so, I gather that could justify a "true" to it

Answer 18

no.... the true false question is this: The height of the pyramid using the 5,12,13 base is 2.4cm is this a true or false statement?

Answer 19

ark, man that's .. different from what you posted... I see

Answer 20

yeah sorry thats what i meant to post with the diagram forget about the first question.

Answer 21

so as I was saying, notice the 5,12,13 triangular face, is UP right now, let's put it DOWN

Answer 22

that is not the same drawing though

Answer 23

so what would be our "altitude" or height? well
keep in mind that, the line as "altitude" coming from a 90 degrees angle like above
will make 3 SIMILAR TRIANGLES
http://www.mathwarehouse.com/geometry/similar/triangles/geometric-mean.php

Answer 24

the 2 smaller ones, are SIMILAR with the BIGGER one containing them, thus 3 similar triangles