Answer:
Isosceles (E) & obtuse (B)
Step-by-step explanation:
Since PQ = QR, △PQR = isosceles triangle (opposite sides are equal).
If, PQ = QR, then, m∠Q = ∠R (measure of opposite angles are same if opposite sides are equal in a triangle).
Then, using Angle sum property,
m∠P + m∠Q + m∠R = 180°
3x - 120 + x - 30 + x - 30 = 180
3x + x + x - 120 - 30 - 30 = 180
5x - 180 = 180, 5x = 180 + 180
5x = 360
x = 72.
So, (3x - 120)° = 96°
(x - 30)° = 42
So, △PQR = obtuse (one angle is < 90°)
=》 Then, △PQR = isosceles (E) & obtuse (B) .
Hope it helps ⚜
