How would i answer this? can you give me the steps? ! (11,12,13)

11) to find the area of a triangle you use the formula A = 1/2(b*h)

so you will need to measure the two shorter sides of the triangle (measured in centimeters), multiply the two numbers together and divide by two

the number you get from that will be in centimeters so to convert it, divide by two again, then multiply by five. that will make your answer be in the proper scale. 
it looks like you measured them to be 3cm and 4cm, so the area would be 25 square meters