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: disagree its backwards
Step-by-step explanation: the x intercept always comes first so its actually (-4,2)
Lets say the base is x and the height is y. The new base would be 1.2x and the new height would be 1.3y
Area of a triangle is base times height divided by 2:
1.2x*1.3y/2 = (1.2*1.3 + x*y)/2 = 1.56xy/2 = 0.78xy = 78% of xy
But a normal area would be 50% of xy
78% - 50% = 38%
ANSWER: 38% increase
