As with any triangle, the sum of angles is 180°.
(a)
(x -5) +(3x +30) +35 = 180 . . . . . sum of angles is 180
4x +60 = 180 . . . . . . . . . . . . . . . . collect terms
4x = 120 . . . . . . . . . . . . . . . . . . . . subtract 60
x = 30 . . . . . . . . . . . . . . . . . . . . . . divide by 4
(b)
Angle A = x -5 = 30 -5 = 25
Angle B = 3x +30 = 3*30 +30 = 120
Answer:
x = 2
Step-by-step explanation:
6x-1=11
Add 1 to each side
6x-1+1=11+1
6x = 12
Divide by 6
6x/6 = 12/6
x = 2
<FCD
<SNP
SN
FC
Look at the vertex of each angle and match it to the other triangle (tri. DFC is congruent to tri. SNP) F=N, which is the vertex, D=S, C=P, DF=SN, and so on