it's wrong because he put a closed circle on the nine when he was supposed to put an open circle because nine is not less than itself but the thing that he did right wad that he went to the left if it was a greater than or equal symbol then it would be correct
hope this helps
mark brianlest
The sector of the circle formed by its two radius of length 12 inches has an area of 24 pi. This is obtained using the formula, Area is equal to the product of pi, radius squared and central angle all over 360.
Based on the given data, the following formula will be useful;
Area of the base, A = pi*r^2
Lateral Area, A(l) = pi*r*sqrt of h^2 + r^2
Surface Area, A(s) = pi*r*(r+sqrt of h^2 + r^2)
Based on the given area of the base, the radius can be calculated and is equal to 3.9088 in. Based on the given lateral area, the h or the lateral edge can be calculated and is equal to 7.8785 in. Given all the information needed, and directly substituting to the above formula for surface area, SA is equal to 156 in^2 (option D)
-2 and 1.
Hope this helps!
Answer:
90
Step-by-step explanation:
90÷2= 45
90÷3=30