The area of triangle ABC ABC is 18 cm2. Side AC=4x AC = 4 x and side AB=x+3 AB = x + 3 . Given that angle A=30∘ , calculate the
1 answer:
Answer:
x = 3
Step-by-step explanation:
Let the altitude from B to AC intersect at point D. Then BD is a height of the triangle with base AC
ΔABD is a 30-60-90 triangle since m∠A = 30
Therefore, AB = 2(BD) or BD = AB/2 = (x+3)/2
Area of the triangle = bh/2 = AC(BD)/2 = 4x(x + 3)/(2)(2)
= x(x + 3) = 18
(x + 6)(x - 3) = 0
x = -6 or x = 3
x cannot equal -6, so x = 3
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Answer:
The value of n is 21.
Step-by-step explanation:
We are given that three of the exterior angle of the n-sided polygon are 50° each two of its interior angle are 127° and 135° and the remaining interior angle are 173 each.
As we know that the sum of all exterior angles of the polygon is 360°. Also, the number of remaining interior angles will be (n - 5).
And, the exterior angle = 180° - the interior angle.
So, according to the question;
150 + 53 + 45 + 7(n - 5) = 360
248 + 7n - 35 = 360
213 + 7n = 360
7n = 360 - 213
7n = 147
n =
n = 21
Hence, the value of n is 21 and this is a 21-sided polygon.