Answer:
A) circumference = 15 cm and area = 9.5 cm²
B) Circumference = 21 dm
Area = 12 dm²
Explanation:
A) circumference is the same as perimeter. Thus;
Circumference = sum of sides = 6 + 4 + 5 = 15 cm
Area = ½ x base x height
Base = 5 cm and height = 3.8 cm
Area = 1/2 × 5 × 3.8 = 9.5 cm²
B) Circumference; C = 10 + 5 + 6 = 21 dm
Area;
The third side of the unshaded triangle is; L = √(5² - 4²)
L = √(25 - 16)
L = √9
L = 3
Total area of both shaded and unshaded region is;
A_t = ½ × (3 + 6) × 4
A_t = 2 × 9
A_t = 18 dm²
To find area of shaded triangle, let's find the area of unshaded triangle and subtract it from area of total triangle.
Thus;
A_unshaded = ½ × 3 × 4
A_unshaded = 6 dm²
Area of shaded triangle is;
A_shaded = 18 - 6 = 12 dm²