I need help with Kumon math level I 187 B

The length of the tangent AB is [tex]\sqrt{2a^{2}+2b^{2} }[/tex] if the radii of the largest circle is a and the radii of the smallest one is b.
It is a line that touches a single point on the circle.
Firstly we have to draw a perpendicular from O to the radii of the smallest circle. In this way AOLB becomes a rectangle. We let the point where the bisector intersect the radii as L.
OA=a
Lb=a also
O'L=b-a
In triangle OLO' we use pythagoras to calculate the value of OL which wil then equal to AB so,
OL=[tex]\sqrt{(b-a)^{2}+(a+b)^{2} }[/tex]
=[tex]\sqrt{2a^{2}+2b^{2} }[/tex]
It will be the length of AB also.
Learn more about circles at https://brainly.com/question/24375372
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