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

Question

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

anonymous · Answer

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

welshfella · Answer

sorry  i misread the question 
here is the diagram again

welshfella · Answer

|dw:1442935469240:dw|

welshfella · Answer

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

anonymous · Answer

5x2.5 = 12.5 so its 12.5 B

welshfella · Answer

no @diamond2.0

welshfella · Answer

its 2.5 * height of the triangle (h)

anonymous · Answer

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

anonymous · Answer

what is it looking for

welshfella · Answer

- or you could use trigonometry as robtobey has done