Answer:
add the 2 equations together
Step-by-step explanation:
i was in class when I heard this so it should be correct
1. Given any triangle ABC with sides BC=a, AC=b and AB=c, the following are true :
i) the larger the angle, the larger the side in front of it, and the other way around as well. (Sine Law) Let a=20 in, then the largest angle is angle A.
ii) Given the measures of the sides of a triangle. Then the cosines of any of the angles can be found by the following formula:

2.

3. m(A) = Arccos(-0.641)≈130°,
4. Remark: We calculate Arccos with a scientific calculator or computer software unless it is one of the well known values, ex Arccos(0.5)=60°, Arccos(-0.5)=120° etc
Answer:
138.16 in²
Step-by-step explanation:
The surface area SA of the cone is the sum of the base area B and the lateral area LA. The lateral area is half the product of the circumference and the slant height. The radius is half the diameter, so is 4 inches.
SA = B + LA
= πr² + (1/2)(2πrh) . . . . where h is the slant height
= (πr)(r +h)
Filling in the numbers, you have ...
SA = (3.14)(4 in)(4 in + 7 in) = 3.14×(44 in²) = 138.16 in²
Please like I’m begging you please