Solution:
Question 3:
The image below gives a vivid explanation of the question
Concept:
The sum of angles in a triangle is
[tex]=180^0[/tex][tex]\begin{gathered} \angle A+\angle B+\angle C=180^0 \\ \angle A=61^0 \\ \angle B=90^0 \\ \angle C=4f+1 \end{gathered}[/tex]By substituting the values, we will have
[tex]\begin{gathered} \angle A+\angle B+\angle C=180^0 \\ 61^0+90^0+4f+1=180^0 \\ \text{collect similar terms, we will have} \\ 61+90+1+4f=180^0 \\ 152^0+4f=180^0 \\ 4f=180-152^0 \\ 4f=28^0 \\ \text{Divide both sides by 4} \\ \frac{4f}{4}=\frac{28}{4} \\ f=7^0 \end{gathered}[/tex]Hence,
The final answer is f = 7°