Algebra Test Help?

Question

find the missing side of the right triangle (round to the nearest tenth if neccasary)
side a=4 side b=7 side c= ?
side a=12 side c=15 side b=?
side b=9 side c=20 side a=?
side a=0.6 side b=0.8 side c=?

I think the last one is 1 im not sure tho

Answer 1

I assume that these are sides of a right triangle so use the pythagorean theorem.

a^2+b^2=c^2
I'm only going to do one example to show you.

side a=4 side b=7 side c=?
(4)^2+(7)^2= c^2
16+49 = c^2
65=c^2
c = sqrt(65)
c= 8.06225774829855
round to the nearest tenth
c= 8.1

Answer 2

Just use pythagorean theorem :)

a^2 + b^2 = c^2 (those ^2 things mean squared)

If you want to find a, its a = square root of (c^2 - b^2)
if you want to find b, its b = square root of (c^2 - a^2)
if you want to find c, its c = square root of (a^2 + b^2)

remember the order of operations, square the numbers first, add them, then find the square root :)

Answer 3

You forgot to mention that c is the hypotenuse.

Use the Pythagorean theorem: a² + b² = c²

Answer 4

c= sqrt(4^2 +7^2) = 8.1
b = sqrt (15^2-12^2) = 9
a = sqrt(20^2-9^2) = 17.9
c = sqrt(.6^2+.8^2) = 1