Step-by-step explanation:
Use triangle congruency:
BC=EC, AC=DC - Given
m∠DCE = m∠ACB because they are vertical angles
Therefore ΔABC ≅ ΔDEC because of Side-Angle-Side congruency
AB=DE because corresponding parts of congruent triangles are also congruent (CPCTC)
Given:
Irregular Shape:
Semi-circle and rectangle:
Area of a rectangle = l * w
Area of a semi-circle = (π r²)/2
Area of rectangle = 8 cm * 5 cm = 40cm²
Area of a semi-circle = (3.14 (4²))/2 = (3.14*16)/2 = 50.24/2 = 25.12cm²
4² is taken from diameter of 8cm divided by 2 to get the radius.
Total area = 40 cm² + 25.12 cm² = 65.12 cm²