Wednesday

April 16, 2014

April 16, 2014

Posted by **Eunice** on Wednesday, April 21, 2010 at 8:23am.

triangles whose sides are 8 cm, 15 cm, and 17 cm long. What is the probability that the

coin lands within one of the triangles?

- math/geometry pls help -
**bobpursley**, Wednesday, April 21, 2010 at 9:38amwell, if it is entirely within, it cannot touch any corner or side.

STart with the area along the sides the center of the coin cannot be in.

The center has to be greater than .5cm from any side. Draw the original triangle. Now mark a line parallel to each side, inside the triangle, .5 from the parallel side. These three lines make a triangle inside, in which the center may reside.

label the inner triangle a, b, c, with the a side parallel to 8, b parallel to 15, and c parallel to 17.

a/8=b/15=c/17 similar triangles.

but a= 8-.5-.5-.5(8/15) If you examine the 17 corner carefully, you can arrive at that with using smaller triangles which are similar.

solve for a: a= 6.86

which means b: b= a*15/8=12.86

area of inner triangle= 1/2 ab=44.1

area of original triangle= 1/2 8*15=60

Pr(coin inside)= areainner/areaouter

**Related Questions**

Geometry - A coin of radius 1 cm is tossed onto a plane surface that has been ...

math - the lengths of the sides of four triangles are listed as follows. which ...

geometry - A plane intersects a sphere that has a radius of 13 cm. The distance ...

Geometry - Triangle I has sides with lengths 2 2/3 cm, 4 1/2 cm and 3 cm. ...

physics - A U.S quarter is rolling on the floor without slipping in such a way ...

physics - A U.S quarter is rolling on the floor without slipping in such a way ...

geometry - Find the surface area of each of the following a cube that is 4 cm by...

geometry - Calculate the lateral and surface areas of a prism whose height is 12...

Geometry - Calculate the lateral and surface area of a prism whose height is 12 ...

math - Triangle I has sides with lengths 2 2/3 cm, 4 1/2 cm and 3 cm. Triangle ...