## MBrecht92 Group Title The base of a triangle exceeds its height by 17 inches. If its area is 55 square inches, find the base and height of the triangle. one year ago one year ago

1. MBrecht92 Group Title

Hello all.

2. prettyboy20202 Group Title

sup

3. MBrecht92 Group Title

Any ideas?

4. prettyboy20202 Group Title

nope

5. MBrecht92 Group Title

I thought I should set up the problem this way: 55 = 1/2(h+h+17)

6. MBrecht92 Group Title

But then I got the wrong answer, as usual

7. mathstudent55 Group Title

let h = height, then let b = base = h + 17 Area of triangle: A = (bh)/2 55 = (h + 17)h/2

8. MBrecht92 Group Title

Right, exactly..so 55 = 2h+17/2, and thus h+17/2 = 55. Then, 55*2 = h+17

9. mathstudent55 Group Title

Your're close, but the formula for the area of a triangle is the base times the height over 2, not the base plus the height over 2.

10. helder_edwin Group Title

right $\large 55=\frac{(h+17)\cdot h}{2}$

11. MBrecht92 Group Title

Um...but I already multiplied the b by the h. It's just that here, b = h + 17

12. mathstudent55 Group Title

it's not (2h + 17)/2 = 55, it's (h^2 + 17h)/2 = 55

13. helder_edwin Group Title

use the distributive law on the denominator

14. helder_edwin Group Title

$\large 55=\frac{h^2+17h}{2}$

15. MBrecht92 Group Title

Okay. So you end up with h^2 + 17h = 110

16. MBrecht92 Group Title

Then...h^2+17h-110

17. mathstudent55 Group Title

Right. Now subtract the 110 to the left and solve the quadratic eq.

18. mathstudent55 Group Title

Set it equal to zero and solve.

19. MBrecht92 Group Title

(x+22)(x-5) = 0, x = -22, 5

20. MBrecht92 Group Title

Sorry...I meant h. So h = 5, and then b = (5) + 17 = 22

21. MBrecht92 Group Title

Thank you for all your help!!

22. mathstudent55 Group Title

Not x, but h. Now you have h = -22 or h = 5. A negative number is meaningless as the height of a triangle, so dicard it. yes, you got it.

23. mathstudent55 Group Title

wlcm