Tuesday

September 2, 2014

September 2, 2014

Posted by **Josh** on Monday, February 23, 2009 at 6:58pm.

- Math -
**Damon**, Monday, February 23, 2009 at 7:38pmb = 3 h -3

area = b h = (3 h - 3)h = 3 h^2 - 3 h = 90

so

3 h^2 - 3 h - 90 = 0

(h+5)(3h-18) = 0

h = 6 is positive real solution

so

b = 3*6 -3 = 15

then perimeter = 2 h + 2 b

- Math -
**Josh**, Monday, February 23, 2009 at 7:54pmdont get it

- Math -
**Josh**, Monday, February 23, 2009 at 8:06pmhow did you get that. not rudely.

- Math -
**PsyDAG**, Tuesday, February 24, 2009 at 10:36amLet B = base and H = height

From the first sentence:

B * H = 90

From the second sentence:

B = 3H - 3

Substitute the value of B from the second equation into the first and solve for H. Put the value of H in the second equation to find B. Check by putting both values into the first equation.

As Damon says, "then perimeter = 2 h + 2 b".

I hope this helps. Thanks for asking.

**Answer this Question**

**Related Questions**

basic geometric - 10. a rectangle has width the same as a side of a square whose...

geometry - the perimeter of a rectangle is 72. the base is 3 times the height ...

algebra - The perimeter of a rectangle is 80x. The base is 7 times the height. ...

Math - The area of a rectangle is 220 square centimeters. The height of the ...

9th grade polynomials - How do you write the expression for the area of the ...

Algebra - The length of a rectangle is three times its width. If the area of the...

maths - the length of a rectangle is 3 less than 5 times its width. Write a ...

pre calc - The length of a rectangle is three times its width. If the area of ...

8th grade - The area of a rectangle is 45cm2. The height is one less than two ...

Math - if a triangle has a perimeter of 50cm one side is double the length of ...