Find the probability that a chosen point at random in the trapezoid shown lies in either of the shaded regions.

Question

anonymous · Answer

attachment

anonymous · Answer

area of the shaded region/ total area of the trapezoid

anonymous · Answer

do you know how to calculate the area of a trapezoid?

anonymous · Answer

no lol im clueless when it comes to math.

anonymous · Answer

so?

amistre64 · Answer

the area of a trap is the average of the bases times the height

amistre64 · Answer

(top+bottom)/2 * height

anonymous · Answer

?

anonymous · Answer

(16+7)/2x4=46?

amistre64 · Answer

yep; thats the total area of the trap

anonymous · Answer

oh how do i find the area of the shaded region

amistre64 · Answer

the shaded parts make up a triangle right?  or you can just find the area of one of them and double it

anonymous · Answer

ok

amistre64 · Answer

lets go with one and then double it; base times height / 2

anonymous · Answer

You can't double it because the two triangles are different sizes.

anonymous · Answer

oh

amistre64 · Answer

the drawing is poor, but it implies an iso trap

anonymous · Answer

base of left trianlge = 5 right has base 4

anonymous · Answer

But the measurements show one triangle with a base of 4 and the other can be calculated as having a base of 5.

amistre64 · Answer

or at least that what O gather from it ... i could be blind :)

anonymous · Answer

ok

anonymous · Answer

yes they look samearea

amistre64 · Answer

illl defer to the majority on this one ..

anonymous · Answer

area of triangle karren is 1/2 * base* height

anonymous · Answer

Total base of the trap is 16, the right triangle has a base of 4, the white rectangle has a base of 7, so the left triangle must have a base of 5 using subtraction 16-7-4=5

amistre64 · Answer

:) i can add on me fingers, but subtraction is rather painful

anonymous · Answer

lol

anonymous · Answer

you'll have to use an abacus amist

anonymous · Answer

so the area of the trap is 46 and the shaded region on the left is 16?

amistre64 · Answer

5*4/2 = 10
4*4/2 = 8

10+8 = 18 for shaded region

anonymous · Answer

ok

amistre64 · Answer

so prob = shaded/total

anonymous · Answer

so that makes the answer 18/46

amistre64 · Answer

yes, and if they are a stickler about it they will want you to simplify the fraction

amistre64 · Answer

9/23 perhaps?

anonymous · Answer

thanks sooo much everbody

curry · Answer

amis help me after this

anonymous · Answer

9/23