Question

Find the length of this right triangle. Give an approximation to 3 decimal places

Answer 1

A triangle always has 180 degrees so to find the missing number do:

21+17+a = 180

38+a=180

180-38=a

a= 42

the answer is 42

Answer 2

According to Pythagoras theorem,

21^2 = 17^2 + a^2
=> a= √(21^2-17^2)
=√152 = 12.329