Hey there! :)
Answer:
SA = 144 cm².
Step-by-step explanation:
Find the surface area by calculating the areas of each of the lateral sides and bases:
In this instance, the bases are triangles, so the formula A = 1/2(bh) will be used:
Bases:
A = 1/2(bh)
A = 1/2(4·3)
A = 1/2(12)
A = 6 cm².
There are two bases, so:
6 × 2 = 12 cm²
Find the areas of the lateral sides using A = l × w:
5 × 11 = 55 cm²
4 × 11 = 44 cm²
3 × 11 = 33 cm²
Add up all of the areas:
12 + 55 + 44 + 33 = 144 cm².
multiply 40 by 3/4
40 x 3/4 = 40*3 = 120, 120/4 = 30
he answered 30 correctly
40-30 = 10, he missed 10
