Apiece of art is in the shape of an equilateral triangle with 7 in. find the area of the piece of art. round to the nearest tenth

Can someone answer this question for me

Asmall book publisher knows that 26 books weigh 41 lbs. how much do 40 books weigh?

Jessa bought a yoyo from a company that claims that, with each retraction, the string rolls up by 60% of the original length. she sets up a tape measure and throws the yoyo 3 times. her data are charted below. throw length of string (feet) 1 3 2 1.8 3 1.08 jessa wants to find the sum of the length of string after 10 throws. what is the sum of the lengths, rounded to the nearest hundredth?