A sphere has a radius of 7 cm. What is the surface area of the sphere?
Practice Questions
Q1
A sphere has a radius of 7 cm. What is the surface area of the sphere?
154 cm²
308 cm²
616 cm²
44 cm²
Questions & Step-by-Step Solutions
A sphere has a radius of 7 cm. What is the surface area of the sphere?
Step 1: Identify the formula for the surface area of a sphere, which is Surface Area = 4πr².
Step 2: Substitute the radius (r) into the formula. Here, the radius is 7 cm.
Step 3: Calculate r² (7²). This means 7 multiplied by 7, which equals 49.
Step 4: Multiply 49 by 4. This gives you 196.
Step 5: Now, multiply 196 by π (approximately 3.14). This means 196 * 3.14.
Step 6: Calculate 196 * 3.14, which equals approximately 615.44.
Step 7: Write the final answer. The surface area of the sphere is 615.44 cm².
Surface Area of a Sphere – The formula for the surface area of a sphere is derived from geometric principles and is given by 4πr², where r is the radius.