Final answer:
The width and length of the rectangle are 19 cm and 26 cm respectively, obtained by setting up an equation with the given perimeter and solving for the width.
Step-by-step explanation:
The student has asked for the dimensions of a rectangle where the length is 7 cm more than its width, and the overall perimeter is 90 cm. To find the length and width, we need to set up two equations using the perimeter formula for a rectangle, which is P = 2l + 2w, where P is the perimeter, l is the length, and w is the width.
Let the width be w cm. Then the length will be w + 7 cm. We use the given perimeter to establish the equation: 90 = 2(w + 7) + 2w. Upon simplifying the equation, we get 90 = 4w + 14, which further simplifies to w = 19 cm for the width. Subsequently, the length will be 19 + 7 = 26 cm.