Answer:
CM = 4
Explanation:
set CM=x and BM=y AM= 7-y
right triangle BMC: x² = 5² - y² = 25 - y² ... (1)
right triangle AMC: x² = (4√2)² - (7-y)² = 32 - 49 +14y - y² = -17 + 14y -y² ...(2)
(1)-(2): 0 = 42 - 14y
14y = 42
y (BM) = 3
x² (CM²) = 25 - 3² = 16
x (CM) = 4 (height is positive)