1. 4 inside angles must sum to 360:
X = 360-45-65-95 = 155
2. All the outside angles must sum
To 360:
2x + 70+ 86 + 9 = 2x + 248
2x = 360-248
2x = 112
X = 112/2 = 56
3. Sum of interior angles for 6 sides figure = 720.
X = 720 - 90-120-130-140-150
X = 90
4. Exterior angles sum to 360
4x +x + 98 + 162 = 360
5x + 260 = 360
5x = 100
X = 100/5
X = 20
Your procedure is perfect, you're fine, however, bear in mind that, in a calculator when plugging in values for some functions, specially trigonometric ones, if you tell it cos(40), and the calculator is in Radian mode, it thinks you meant cosine of 40 radian units, if you give it cos(40) and it's in Degree mode, it thinks you meant 40°, and 40 radians is hugely different than 40°.
so, make sure your calculator is in Degree mode, as you'd have guessed, it isn't.
Volume formula of a sphere:
r³
given:
r = 3
V =
(3)³
V =
× 27
V = 36
units³ (in terms of
)
V = 113.097 units³ ≈ 113.1 units³
№1. Given: r=8 ft, π≈3.14
C=2×π×r=2×3.14×8=50.24=50.2 ft
A=π×r²=3.14×64=200.96=201 ft²
Answer: 50.2 ft; 201 ft²
№2. Given: D=11 cm, π≈3.14
d=2r or r=2/d, so if d is 11 cm, then r is 11÷2=5.5 cm
C=2×π×r=πD=3.14×11=34.54=34.5 cm
A=π×r²=3.14×(5.5)²=94.985=95 cm²
Answer: 34.5 cm; 95 cm²
