If u can answer this that would rlly help:)

x = 12

Step-by-step explanation:

First, we need to find the last interior angle of the triangle. Since we know the exterior angle next to it is 140° and they are supplementary, meaning they form a 180° angle, we can make an equation to solve for the last angle.

∠SRT + 140° = 180°

∠SRT = 40°

Now we know that the last interior angle is 40°. All triangles have a sum of 180°, therefore we can once again set up an equation to solve for x.

3x + 4 + 8x + 4 + 40 = 180

11x + 48 = 180

11x = 132

x = 12

Therefore, x = 12.

the surface area is 124cm²

step-by-step explanation:

length: 4cm

width: 9cm

height:   2cm