Answer:
12∠x∠16
Step-by-step explanation:
For the triangle to be acute,a²+b²+c²,
Where c is the largest side of the triangle.
Hence, we must say x²+(x+4)²≥20²,
or after simplifying, x²+4x-192≥0 or (x+16)(x-12)≥0
Since x must have positive values only, x≥12
Therefore, for the triangle to be acute,we must have 12≤x≤16.
