Answer:
a = 20 cm
Step-by-step explanation:
Since the triangle is right use Pythagoras' identity to solve for a
The square on the hypotenuse is equal to the sum of the squares on the other two sides, that is
a² + 21² = 29²
a² + 441 = 841 ( subtract 441 from both sides )
a² = 400 ( take the square root of both sides )
a = [tex]\sqrt{400}[/tex] = 20
