The length of side b is also probably 3cm, because thinking of a diamond shape, all of the sides are equal and It give you no other measurments
2) The area is 1.1 m^2 because to find the area the formula is width*length. SO you would separate it. It would be 0.9 * 1 = 0.9 and 0.4 * 0.5 = 0.2. Then you add it together. So it would be 1.1 m^2. The perimeter is all the sides added together so 4.2 m, but it says mm so you have to convert it and you get 4200.
4) Area is 1.16 cm^2. Again you would seperate it. So, 1 * 1 = 1 and .2 * .8 = .16. Then you add it together and get 1.16 cm^2. The perimeter is all the sides added up. You get 4.2 cm.
A and T are points. On their own, they cannot define a line. So we can rule out choice A
WCR and TRA are angles. For any triple the points do not fall on the same straight line. So we cannot define any lines here. This crosses off choice B
Choice C is the answer because WC does define a line. We only need two points to form a line. Similarly CR does the same job. We draw a line marker with two arrows at each end to be placed over the letters to indicate "line".
Choice D is similar to choice D; however, it is not the answer because WT is the same line as WC. In other words, WC = WT. We haven't named a new line at all. We're simply repeating ourselves.