Triangle ABC is an isosceles triangle.
Solution:
Given data:
∠ABC = 70° and ∠ACD = 55°
<em>If two parallel lines are cut by a transversal, then alternate interior angles are congruent.</em>
m∠BAC = m∠ACD
m∠BAC = 55°
<em>Sum of the angles in a straight line add up to 180°.</em>
m∠ACD + m∠ACB + m∠ABC = 180°
55° + m∠ACB + 70° = 180°
m∠ACB + 125° = 180°
Subtract 125° from both sides, we get
m∠ACB = 55°
In triangle ABC,
∠BAC = 55° and ∠ACB = 55°
∠BAC = ∠ACB
Two angles in the triangle are equal.
Therefor triangle ABC is an isosceles triangle.
To find the total area of this figure, it would be easiest to find the area of the left part (rectangle) and then find the area of the right part (triangle), and then add the two area values together.
First, we will find the area of the rectangle, using the formula A = lw, where l is the length of the rectangle and w is the width of the rectangle.
The length of the rectangle is 13 cm and the width is 9 cm. If we substitute in these values into our equation, we get:
A = (13cm)(9cm)
A= 117 cm^2
Next, let’s find the area of the triangle, using the formula A=(1/2)bh, where b is the base of the triangle and h is the height.
The base of the triangle is 11 cm and the height of the triangle is 5 cm (found by subtracting 13-8 as seen in the figure). If we substitute in these values and simplify, we get:
A=1/2(11cm)(5cm)
A=1/2(55cm^2)
A=27.5 cm^2.
When we add together the area of the rectangle with the area of the triangle, we will get the total area of the figure.
117 cm^2 + 27.5 cm^2 = 144.5 cm^2
Your answer is 144.5 cm^2 or the first option.
Hope this helps!
1.
Answer D.
2.
From secant theorem, we know, that:
and from picture:
So we can calculate:
Answer:
Option B) 4 centimeters
Step-by-step explanation:
see the attached figure to better understand the problem
step 1
Find the value of n
we know that
a) GJ is a midsegment of triangle DEF
then
G is the midpoint segment DF and J is the midpoint segment EF
DG=GF and EJ=JF
b) HK is a midsegment of triangle GFJ
then
H is the midpoint segment GF and K is the midpoint segment JF
GH=HF and JK=KF
In this problem we have
HF=7 cm
so
GH=7 cm
GF=GH+HF ----> by addition segment postulate
GF=7+7=14 cm
Remember that
DG=GF
substitute the given values
solve for n
step 2
Find the length of GJ
we know that
The <u><em>Midpoint Theorem</em></u> states that the segment joining two sides of a triangle at the midpoints of those sides is parallel to the third side and is half the length of the third side
so
we have
substitute
step 3
Find the length of HK
we have that
----> by the midpoint theorem
we have
substitute
Answer: X = 2
Step-by-step explanation: