ANSWER
C. 58°
EXPLANATION
The sum of the interior angles of a triangle is 180°.
We sum all the three angles to obtain,
.
We group like terms to get,
.
Simplify,
.
Combine like terms to get,
.
Simplify,
.
Divide both sides by 32 to get,
.
We substitute the value of x into the expression for
.
This implies that,
.
.
.
The correct answer is C
Since the area of a triangle is in the form
area=0.5(base)(height)
height=base+7
let base=x
area=0.5(x)(7+x)
30=3.5x+0.5x^2
multiply the equation by 2
60=7x+x^2
subtract 60 from both sides
x^2+7x-60=0
(x-5)(x+12)=0
thus x=5 or x=-12 since we are only considering positive answers
x=-12 is rejected
so base=5 and height=5+7=12
1000 j etyuu was the night of my school week I am so