In ΔABC, a = 660 cm, b = 680 cm and c=100 cm. Find the measure of ∠B to the nearest degree.
2 answers:
Answer:
m∠B = .
Step-by-step explanation:
Since the three sides of the triangle are given, then we apply cosine rule.
=
+
- 2ac Cos B
But, a = 660 cm, b = 680 cm, and c = 100 cm.
So that;
=
+
-2(660 x 100) Cos B
462400 = 435600 + 10000 - 132000 Cos B
462400 = 445600 - 132000 Cos B
132000 Cos B = 445600 - 462400
= -16800
Cos B =
= -0.1273
B = -0.1273
=
Thus, measure of ∠B is .
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Given:
The area of the cross-section is 55cm².
The volume of the prism is 330cm³.
To find:
The length of the prism.
Solution:
We have,
Area of the cross-section = Area of base = 55 cm²
Volume of the prism = 330cm³.
Let x be the length(height) of the prism.
We know that,
Therefore, the length of the prism is 6 cm.
Answer:
b
Step-by-step explanation:
The equation of a line in slope- intercept form is
y = mx + c ( m is the slope and c the y- intercept )
Calculate m using the slope formula
m = (y₂ - y₁ ) / (x₂ - x₁ )
with (x₁, y₁ ) = (- 1, 2) and (x₂, y₂ ) = (3, 1)
m = = -
, thus
y = - x + c ← is the partial equation
To find c substitute either of the 2 points into the partial equation
Using (- 1, 2), then
2 = + c ⇒ c = 2 -
=
y = - x +
← in point- slope form
Multiply through by 4
4y = - x + 7 ( add x to both sides )
x + 4y = 7 → b