It does not contain an equal sign. It cannot be solved for unless the value of the variable is given.
Hey i think the only mistake i caught was when you put 3 points under the line mark instead of only needing 2.
Possibly another mistake at 3a, Only 2 points (but i could be wrong)
13) b=145 because a line equals 180° so you subtract 35° from 180°
14) b=61 because it as right angle so 90 minus 29 equals 61
15) b= 23 because 360 is a full circle so you add 243 and 94 and get 337 then subtract 337 from 360
16)b=131 because you subtract 49 from 180
17) b=90 because you subtract 90 from 180
18) b=73 because of vertical angles
The area of the sector is 86.81π mm²
<u>Explanation:</u>
Given:
Radius of the sector, 25mm
Angle, α = 50°
Area of the sector, A = ?
We know:
Area of the sector = 
On substituting the value, we get:

Therefore, the area of the sector is 86.81π mm²