Answer: 90°
Explanation: the sum of all the angles in a triangle = 180. So 70 + 30 = 90 and 180-90=90
Yes, they're equivalent values.
Answer: Rectangle around the cylinder, Lateral surface of the cone, Half a sphere
To find this surface area, you have 3 different parts. First, you need the rectangular portion of the cylinder, because the circles will be on the inside of the composite shape. Then, you will need the lateral side of the cone, that's everything but the circular base. Again, the circle will be on the interior. Finally, you should find the surface area of half of the sphere.
The answer to that question is C
