Plz i need on this i do not get it

Area of circle 1 = πr² 
Area of circle 1 = π (10)²
Area of circle 1 = 100π km²

Area of circle 2 = πr²
Area of circle 2 = π (5)²
Area of circle 2 = 25π km²

Number of times the bigger circle is greater than the smaller circle 


------------------------------------------------------------------------------------
The big circle is 4 times greater than the small circle.
------------------------------------------------------------------------------------

We know that the area of a circle is . The relationship between area and radius is a quadratic relationship. So we know that the ratio of the areas of the circles will be equal to the ratio of the squares of the radii of the circles.

The ratio of the squares of radii between circle 1 and 2 are , which is equal to four. Thus, the area of circle 1 is four times larger than the area of circle two.

Step-by-step explanation:

No , theres not enough information provided to Prove that both the triangles are congruent. Here in the figure we can see that there are two triangles ∆ BDA and ∆ BDC. And its given that

AB = BC BD = BD ( common side )

The congruence conditions for two ∆s are :-

1) SAS ( Side Angle Side )

→ Two triangles are said to be congruent by SAS if two respective sides of the two triangles and the included angle between two sides are equal.

2) AAS ( Angle Angle Side )

→ Two triangles are said to be congruent by AAS if two angles and one side of triangle is congruent to other two angles and one side of the triangle .

3) SSS ( Side Side Side )

→ Two triangles are said to be congruent by SAS if all the three sides of one triangle is equal to three sides of the other triangle.

4) RHS ( Right Hypotenuse Side )

→ In two right-angled triangles, if the length of the hypotenuse and one side of one triangle, is equal to the length of the hypotenuse and corresponding side of the other triangle, then the two triangles are congruent.

And the given data doesn't satisfies any of the conditions.

Hence there is not enough information provided to Prove that two triangles are congruent .