Math Is Fun Forum

kaken

Guest

Triangle

Hi! I was wondering.. how would you go into solving the perimeter and the area of this triangle with the data given. Thank you

Dionysus

Member

Registered: 2006-03-06

Posts: 9

Re: Triangle

I'm assuming H is the height, making H perpendicular to BC.
Therefore triangle abh is a right triangle, so by using pythagorean theorem,

:
144-81=63
Square root that to get 3√7 for B
You can do the same thing for the triangle on the right. adding

:
9 + 81 = 90
Simplify root 90 to get 3√10 for D
This makes your total perimeter 12+3√10+3√7+3 = 15+3√10+3√7 or about 32.4241

To find the area just find the base B + C = 3√7 + 3 and multiply it by your height of 9, and dividing by 2. The answer comes out to be exactly:

+

or about 49.2176.

So to sum up, your appx area is 49.2176, and your apprx perimeter is 32.4241. If you need it exact, look above for the radicals. (All in feet)

kaken

Guest

Re: Triangle

I'm assuming H is the height, making H perpendicular to BC.
Therefore triangle abh is a right triangle, so by using pythagorean theorem,

:
144-81=63
Square root that to get 3√7 for B
You can do the same thing for the triangle on the right. adding

:
9 + 81 = 90
Simplify root 90 to get 3√10 for D
This makes your total perimeter 12+3√10+3√7+3 = 15+3√10+3√7 or about 32.4241

To find the area just find the base B + C = 3√7 + 3 and multiply it by your height of 9, and dividing by 2. The answer comes out to be exactly:

+

or about 49.2176.

So to sum up, your appx area is 49.2176, and your apprx perimeter is 32.4241. If you need it exact, look above for the radicals. (All in feet)

Oh! I see what you mean.. Thanks!

krassi_holmz

Real Member

Registered: 2005-12-02

Posts: 1,905

Re: Triangle

Well done, Dionysus!
Very good!

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Dionysus

Member

Registered: 2006-03-06

Posts: 9

Re: Triangle

Thank You