Answer:
x=54, acute scalene triangle
Step-by-step explanation:
1st Question:
Triangle SRT has two congruent sides, making it an isosceles triangle.
In isosceles triangles, the two base angles are congruent.
This means that in the question, ∠SRT equals ∠STR, so let's call them both x.
The sum of the interior angles of a triangle add to 180, so
∠RST+∠SRT+∠STR=180
Substitute ∠RST for 72 and ∠SRT+∠STR for x
72+2x=180
2x=108
x=54
2nd Question:
Again, using the sum of the interior angles of a triangle, we can say
42+88+∠DFE=180
∠DFE=50
All the angles in the triangle are less than 90°, meaning they are all acute. Also, none of the sides are labeled as congruent, so it is an acute scalene triangle