Answer:
r = 22.629
Step-by-step explanation:
Using the Pythagorean theorem:
(35 + r)² = 53² + r²
1225 + 70r + r² = 2809 + r²
subtract r² from each side of the equation:
1225 + 70r = 2809
subtract 1225 from each side:
70r = 1584
