Answer:
9.6 square inches.
Step-by-step explanation:
We are given that ΔBAC is similar to ΔEDF, and that the area of ΔBAC is 15 inches. And we want to determine the area of ΔDEF.
First, find the scale factor <em>k</em> from ΔBAC to ΔDEF:

Solve for the scale factor <em>k: </em>
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Recall that to scale areas, we square the scale factor.
In other words, since the scale factor for sides from ΔBAC to ΔDEF is 4/5, the scale factor for its area will be (4/5)² or 16/25.
Hence, the area of ΔEDF is:

In conclusion, the area of ΔEDF is 9.6 square inches.
8c-3d is the correct answer
A fraction could be -3 1/6
Answer:
5.2 in
Step-by-step explanation:
An equilateral triangle is a triangle with 3 equal sides
Divide the equilateral triangle into two congruent triangles and use Pythagoras theorem to find the height
The Pythagoras theorem : a² + b² = c²
where a = height
b = base = 6 in / 2 = 3 in
c = hypotenuse = 6 in
6² = 3² + h²
h = 36 - 9 = 27
√27 = 5.196 inch
to the nearest tenth = 5.2 in
the tenth is the first number after the decimal place. To convert to the nearest tenth, look at the number after the tenth (the hundredth). If the number is greater or equal to 5, add 1 to the tenth figure. If this is not the case, add zero