Answer: triangle sum , x= 9
Step-by-step explanation:
The triangle angle sum theorem states that the 3 interior angles of a triangle sum to 180 degrees. Add all of the angle measures together and set equal to 180. (3x-4)+(5x-7)+(13x+2) = 180. Combine like terms. 21x -9 = 180. Add 9 to both sides. 21x= 189. Divide both sides by 21. X = 9
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.
(x2 +1) (x2-4) (mark as brainiest)
Answer:
search up-area of circle formula and circumference of a circle formula
Step-by-step explanation: