First u do a squared +b squared =c squared aka pythagorean theorem then so u already have c squared so you would do 5x5=25 and 13x13=169 so then the equation would be 25+?=169 then do 169-25 which equals 144 and then do the square root of that which is 12 THE ANSWER IS 12
Answer:
x=3
Step-by-step explanation:
2(x-1)=4
2x-2=4
2x=4+2
2x=6
x=6/2=3
Answer:
4
step by step:
b-9=4
Answer:
If it's not too late by now, the answer is 19.9 
A given angle measures 90°.. Then, note that the total measurement of the triangle is 180°... Subtract 180° by 90°, and the other angles must add up to 90°!
Good luck!