Question

give me answers plzz..​

Answer 1

Answer:

Step-by-step explanation:

5) sum of measure of all angle of triangle is 180

take any three angles

m<a +m<b+ m<c =180°

take all angles as x

x+x+x = 180

3x =180°

x=60

so, all the angles of triangle are 60°

6) Side BA is produced to D such that AD = AB

(see Fig. 7.34). Show that 2 BCD is a right angle​

7)  We know that,

(a + b + c)²

= a² + b² + c² + 2ab + 2bc + 2ca

Now,

(2x - y + z)²

= {2x + (- y) + z}²

= (2x)² + (- y)² + (z)² + {2 × 2x × (- y)} + (2 × 2x × z) + {2 × (- y) × z}

= 4x² + y² + z² - 4xy + 4xz - 2yz,

which is the required expansion.

9)Let first side be 3x

Let second side be 5x

Let third side be 7x

Perimeter= 300

Therefore,

3x + 5x + 7x = 300

8x + 7x = 300

15x = 300

x = 300/ 15

x= 20

Therefore, the value of x= 20

1st side= 3x = 3× 20 = 60

2nd side= 5x = 5× 20 = 100

3rd side = 7x = 7× 20 = 140

10)Given - Each side of the equilateral triangle = 6 cm

Area of the equilateral triangle = √3/4 × a² (Where a = side of the equilateral triangle)

⇒ √3/4 × (6)²

⇒ (1.732 × 36)/4

⇒ 1.732 × 9

⇒ 15.588 cm²

So, the area of given equilateral triangle is 15.588 cm²

so bro could not help u with the 8th one

if the answers has helped u please mark me as brainliest

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