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
25.2 / 7.8 = ~ 3.23 hope that helps
Answer:
147°
Step-by-step explanation:
The measure of arc CH is equal to the central angle it sees
the angles arc AH sees are BAC and CAH so the length of arc AH would be the sum of these two angles
90° + 57° = 147°
