## annmeez one year ago Find the area of the triangle, given that it has a perimeter of 15 inches. Round the answer to the nearest tenth. https://media.edgenuity.com/evresources/2091128_cdd0342c-8ba2-4b6b-9a70-a3a8a3c2be63.png A. 10.8 square inches B. 12.5 square inches C. 21.7 square inches D. 97.4 square inches using herons formula to solve

1. anonymous

its an equilateral triangle so a sides are 5 including the height so it B

2. welshfella

sorry i misread the question here is the diagram again

3. welshfella

|dw:1442935469240:dw|

4. welshfella

equilateral triangle so each side has length 15/3 = 5 the perpendicular line h cuts the base of the triangle in half find h using pythagoras theorem Area = h * 2.5

5. anonymous

5x2.5 = 12.5 so its 12.5 B

6. welshfella

no @diamond2.0

7. welshfella

its 2.5 * height of the triangle (h)

8. anonymous

$\frac{5}{2} 5 \sin (60 {}^{\circ})=\frac{25 \sqrt{3}}{4}=10.8253$

9. anonymous

what is it looking for

10. welshfella

- or you could use trigonometry as robtobey has done