What is the surface area of 10,13,5
You multiply each set of two numbers, and double them:
10 * 13 = 130 --> 130 * 2 = 260
10 * 5 = 50 --> 50 * 2 = 100
13 * 5 = 65 --> 65 * 2 = 130
Add the three results together:
260 + 100 + 130 = 490