Use Pythagoras's theorem.

Now, minus 12 from 15:
15 - 12 = 3,
which you need to square.
So the length of a = 9cm.
You can also do:

Which gets 9.
Hope this helps.
The remainder is two hope I could help you
Answer:
Area of triangle: 18
Area of semicircle: (9pi)/2
perimeter of triangle: 20.49
perimeter of semicircle: 3pi+6
perimeter of whole thing: 23.91/ 6+8.49+3pi
Step-by-step explanation:
triangle area: 1/2bh, 1/2*6*6=18
Area of circle: pir^2, 3^2*pi, 9pi, semicircle means half, 9pi/2
Answer:
25 divided by 1/4
Step-by-step explanation:
Answer: 86
Step-by-step explanation: