Answer: 
a=-3
b=-9
Step-by-step explanation:

Diameter of semicircle is 4 cm
so cicumference of circle is 4pi
since there are 4 semicircles, they add up to 2 circles
so total perimeter is 8pi
which when rounded off is 25.13 cm (2d. p.)
Answer:
50° F
Step-by-step explanation:
To convert C° to F°, Multiply the celcius temperature by 9/5, then add 32 to it.
10 x 9/5 = 18
18 + 32 = 50