Answer:
19.2cm²
Step-by-step explanation:
Given parameters:
Radius of the circle = 7cm
Angle subtended by the arc = 45°
Unknown:
Area of the sector = ?
Solution:
To find the area of the sector, use the expression below;
Area of sector =
where r is the radius ;
Insert the parameters and solve;
Area of sector = x
x 7²
Area of sector = 19.2cm²
because the triangle above is an isosceles triangle, then both angles are of the same value.
and one thing you should know, the angle above shows the straight angle.
<em>so the sum of all angles is 180</em><em>°</em>
<u>can be written like </u><u>this</u><u> </u><u>:</u>
(5x+13)°+(3x+7)°=180°
5x + 13 + 3x + 7 = 180
8x + 20 = 180
8x = 180 - 20
8x = 160
x = 20
<em>(*the third choice is correct)</em>
