Question

The lines l and m are parallel to each other.
Find the value of x.
Hence find both the angles


9TH ONE PLS I BEG YOU MY EXAMS

Answer 1

Answer:

x = 18 , 7x – 20 = 106° and 3x + 20 = 74°

Step-by-step explanation:

As the sum of corresponding angles is 180 °

(7x – 20) + (3x +20) = 180

10x = 180

X = 180/10

X = 18

∴  7x – 20 = 7 × 18 – 20 = 106 °

   3x + 20 = 3 × 18 + 20 = 74 °

Answer 2

Answer:

8)=Here, The area of Triangle is 480cm^2

9)=Here, The value of x=18 and angles are 106° and 74° respectively.

Step-by-step explanation:

8)=Perimeter of the triangle=120cm

Ratio of sides=5:12:13

Let the sides be with x

So, perimeter=sum of all sides

=120=5x+12x+13x

=30x=120

=x=120/30

=x=4

So, now its sides are=1st side=5×4=20cm

=2nd side=12×4=48cm

=3rd side=13×4=52cm

Now, Let its sides be a, b and c respectively.

=By applying Heron's formula, we get,

=Area=root[(S(S-a)(S-b)(S-c)] Where, S=1/2(a+b+c)

=S=1/2×(20+48+52)

=S=1/2×120

=S=60cm

Now, Area=root[60×(60-20)(60-48)(60-52)]

=Area=root[60×40×12×8]

=Area=root[2×2×3×5×2×2×2×5×2×2×3×2×2×2]

=Area=480cm^2 (Answer)

9)=Here, As per our given question,

=(7x-20°)+(3x+20°)=180° [Sum of Corresponding angles between parallel lines is 180°]

=7x+3x=180°

=10x=180°

=x=180/10

=x=18

Now, First angle=7×(18)-20=

=126-20

=106°

Now, Second angle=3×(18)+20

=54+20

=74° (Answer).

Thank you.