Answer:
We use cosine rule also called cosine law which states
c^2=a^2+b^2-2abcosC
given
a=8cm, b=7cm, c=9cm cos C?
9^2=8^+7^2-2*8*7 cos C
expand
81=64+49-112 cos C
like terms together
81-113=-112 cos C
-32=-112cos C
multiply both sides by -1
32=112cos C
divide both sides by 112
32/112=cos C
cosC=0.2857
find cos inverse of 0.2857
angle C= 73.40
Answer:
I know 4 people that are all really close friends and all have birthdays in march.
Step-by-step explanation:
Answer:
A) 2b+24x
Step-by-step explanation:
7b+3x-5b+21x
7b-5b+3x+21x
2b+3x+21x
2b+24x
Answer:
if ABCD is a rhombus then the diagonal of rhombus bisect it into two equal triangles.
Step-by-step explanation:
In triangles ABC and CDA,
- AB= CD (S) because rhombus has equal sides.
- BC = AD (S) as as reason 1.
- AC= AC (S) being common side of both triangles
so the triangles are congruent to each other by S.S.S. fact/ axiom