Answer: 210
Step-by-step explanation:
Recall that the perimeter is the distance around the figure. It's the amount of fencing needed to enclose such a shape.
Add up all three sides and set the sum equal to the perimeter 70. Then solve for x.
side1+side2+side3 = perimeter
(3x)+(3x-1)+(4x+1) = 70
10x = 70
x = 70/10
x = 7
We can then calculate each side
- horizontal leg = 3x = 3*7 = 21
- vertical leg = 3x-1 = 3*7-1 = 21-1 = 20
- hypotenuse = 4x+1 = 4*7+1 = 28+1 = 29
Notice how 21+20+29 = 70 to confirm we have the correct side lengths.
Once we know the horizontal and vertical leg (aka base and height), we can find the area.
Area = 0.5*base*height
Area = 0.5*21*20
Area = 210 square cm