Someone please help me in this please.

for the number 13

Step-by-step explanation:

by Pythagoras theorem

x= √81+36

x= √117

punch square root of 117 with a calculator, I don't have one now

step-by-step explanation:

the original amount doesn't ''re just looking for the time it takes for 1/2 of the substance to we have

(1/2) =)     take the ln   of both sides

ln (1/2)   = )   and we can write

ln(1/2) = ) lne     and lne   = 1     so we have

ln(1/2) = -.1092t     divide both sides by -.1092

t = ln(1/2)/-.1092 = about 6.347 days = about 6.3 days (rounded)

b

step-by-step explanation:

it have 5 sides and 5 identicle angle.the rest does not have the same property as b.

brainliest