Answer:
ABC shaded area = 36
- 72 cm²
ABC shaded area perimeter =
cm
ABCD area =
cm²
ABCD perimeter =
cm
Step-by-step explanation:
<u>Shape ABC</u>
Assuming you want the area and perimeter of the shaded part of the shape only...
<u>Area</u>
Area of a sector =
(where r is the radius and
<em> </em>
⇒ area of a sector = 
Area of triangle = 1/2 x base x height
⇒ area of triangle = 1/2 x 12 x 12 = 72 cm²
Therefore, area of shaded area = area of sector - area of triangle
⇒ area = 36
- 72 cm²
<u>Perimeter</u>
Arc length =
(where r is the radius and
<em> </em>
⇒ arc length = 
Hypotenuse of triangle =
(where a and b are the legs of the right triangle)
⇒ hypotenuse =
cm
Therefore, perimeter = arc length + hypotenuse
⇒ perimeter =
cm
<u>Shape ABCD</u>
<u>Area</u>
Area of a semicircle =
(where r is the radius)
⇒ area of large semicircle ABC = 
⇒ area of small semicircle AD = 
⇒ area of shape ABCD = 
<u>Perimeter</u>
1/2 circumference = 
⇒ perimeter = 