Answer:
1) x = 71°, 2) x = 27°, 3) x= 32°
Explanation:
1) Rectangle ABCD.
∠D = 90°
From ΔABE.
∠EAB +∠ABE + ∠BEA = 180°
45 + 90 +∠BEA = 180
∠BEA = 45
∠BEA + ∠AED +∠DEC = 180 °, because ∠BEC is a straight angle
45 + x + 64 = 180
x = 71°
2) Δ XYZ is equilateral, all angles = 60°.
∠YZX = 60°.
∠YZW = 180°, because it is a straight angle.
∠YZX + ∠XZW= 180
60 + ∠XZW= 180
∠XZW = 120.
From ΔXZW
∠ZXW + ∠XWZ + WZX = 180
x + 33 + 120 = 180
x = 27°
3) In ΔPQR,
PQ = PR, so ∠PQR = ∠PRQ = 69°
∠PRQ + ∠PRS = 180, because ∠QRS = 180° as straight angle.
∠PRQ + ∠PRS = 180
69 + ∠PRS = 180
∠PRS = 111°.
From ΔPRS
∠PRS + ∠RSP + ∠SPR = 180
111 + 37 + ∠SPR = 180
111 + 37 + x= 180
x = 32