Answer:

Step-by-step explanation:
we know that
Using proportion

Answer:
Step-by-step explanation:
You need to solve the area sector of the bigger circle. Since we now the length of sector is 270, we can set up an equation.
Length of sector DC = 2
r
270 = 2
(8+OA) *(8+OA is the raidus of the bigger circle/sector)*
270/2
= 8 + OA (division)
135/
-8 = OA
135/
-8 = OB (because OA and OB are the raidus of the same circle, so they are congruent)
I hope this helps you! Please correct me if you see a miscalculation <3<3
Answer:
- 494
Step-by-step explanation:
Breaking down the summation into it;s component parts
= 4k -
k(k + 1) ← substitute k = 19
= (4 × 19 ) - 1.5 × (19 × 20)
= 76 - (1.5 × 380)
= 76 - 570
= 494
Answer: The answer is A and D