The measure of its complementary angle is 87 degrees. When two complimentary angles are added to each other they equal 90 degrees.
Step-by-step explanation:
Answer:
Step-by-step explanation:
<u>This is an AP with:</u>
- The first term a₁ = 12
- Common difference d = 3
- Number of terms n = 40
<u>Number of the seats:</u>
- Sₙ = 1/2*n(a₁ + aₙ) = 1/2n(2a₁ + (n - 1)d)
- S₄₀ = 1/2*40(12*2 + 39*3) = 2820 seats
<u>Formula of nth term:</u>
- aₙ = a₁ + (n - 1)d
- aₙ = 12 + (n - 1)*3 = 12 + 3n - 3 = 3n + 9
- aₙ = 3n + 9
