Step-by-step explanation:
law of cosine :
c² = a² + b² - 2ab×cos(C)
with c being the side opposite of C.
so, in our case
3² = 3² + 3²×3 - 2×3×3×sqrt(3)×cos(A)
0 = 3²×3 - 18×sqrt(3)×cos(A)
27 = 18×sqrt(3)×cos(A)
cos(A) = 27/(18×sqrt(3)) = 3/(2×sqrt(3)) =
= 0.866025404...
A = 30°
FYI : since it is an isoceles triangle, C = A = 30°.
and therefore B = 180 - 30 - 30 = 120°.
as the sum of all angles in a triangle is always 180°.
Answer:
225
Step-by-step explanation:
We can model this question with:
9 = 0.04x
x represents "what number."
0.04x = 9.
Divide 0.04 from both sides
0.04x ÷ 0.04 = 9 ÷ 0.04
9 ÷ 0.04 = 225.
Therefore, 9 is 4% of 225.
Answer:
B
Step-by-step explanation:
The SA of a cone is A=pi*r^2+pi*r*s
So instead of pi*5^2, it should be pi*3*5 (5 is the length of the slant).
1-(24.5/100)=0.755 which will be our multiplier
5400 x 0.755 = $4077 left in his account
5400-4077=$1323 decrease
