Answer:
1. half circle: C = (2πr) / 2
a. C = (2π4) / 2 ≈ 12.566
2. triangle:
a. find slant / hypotenuse.
i. 4² + 10² = c²
ii. 16 + 100 = c²
iii. c² = 116
iv. c ≈ 10.770
b. add both slants to find triangular area
i. 10.77 + 10.77 ≈ 21.54
3. add:
a. 12.566 + 21.54 ≈ 34.106 cm
hope this helps :)