Question

The diagram shows a triangle.

All the measurements are in cm.
The perimeter of the triangle is 70 cm.
The area of the triangle is A cm.
Work out the value of A.
4x + 1
3x - 1
-
Зх

Answer 1

Step-by-step explanation:

first you have to find x . Then you can add them and equal them with triangle area.

Answer 2

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