Answer
a = 24
Work Step by Step
We will use given data about triangle ABC and Pythagoras Theorem to solve for 'a'-
We know that -
$c^{2} =a^{2} + b^{2}$ ( Pythagoras Theorem)
Therefore -
$a^{2} =c^{2} - b^{2}$
$a^{2} = (26)^{2} - (10)^{2}$
$a^{2} = 676 - 100$
$a^{2} = 576$
Therefore $ b = \sqrt (576)$
a = 24
