Answer:
72°
Step-by-step explanation:
Let the 2 equal angles be x then the third angle is x + 18
The sum of the 3 angles in a triangle = 180°, thus
x + x + x + 18 = 180, that is
3x + 18 = 180 ( subtract 18 from both sides )
3x = 162 ( divide both sides by 3 )
x = 54
Hence
the largest angle = x + 18 = 54 + 18 = 72°
We have an isosceles triangle;
A=opposite angle side a.
B=opposite angle side b.
C=opposite angle side c.
A=B
Method 1:
We can divide the isosceles triangle in two right triangles,
hypotenuse=7
side=9/2=4.5
B=A=arccossine (4.5/7)=49.994799...º≈50º
C/2=90º-50º=40º ⇒ C=2*40º=80º
Answer:
a=7; A=50º
b=7; B=50º
<span>c=9; C=80º
Method 2:
Law of cosines:
a²=b²+c²-2bcCosA ⇒CosA=(a²-b²-c²)/(-2bc)
CosA=(49-49-81) / (-126)=0.642857
A=arco cos (81/126)≈50º
B=A=50º
A+B+C=180º
50º+50º+C=180º
C=180º-100º
C=80º
Answer:
</span>a=7; A=50º
b=7; B=50º
<span>c=9; C=80º</span>
Answer:
55.8
Step-by-step explanation:
