Answer:
151.5 cm^2
Step-by-step explanation:
lets cut stright acrros so you have a triangle 13 (base) by 3 cm (high)
area of a triangle is 1/2 base times hight --> 13x3/2 = 19.5cm^2
now lets doi the rectangle that is 12 by 11
Length times hight is the area is 132
add both areas 132 + 19.5
Yep!
Weighing #1: Start off by splitting the pile of 12 coins evenly into two piles, 6 in each pile. Put one pile on each side of the balance. The side that is weighed down has the fake coin it in. Ignore the other 6 coins.
Weighing #2: Now you have 6 coins left. Split the pile evenly again, 3 in each pile. Repeat the same process and put each pile on one side of the balance. The side that is weighed down has your fake coin in it. Ignore the other 3 coins.
Weighing #3: You have 3 coins left. Take two coins, whichever two you like, and weigh them. If they weigh the same, then the one you didn't weigh is the fake one. If one is heavier, then that heavier one is your fake coin.
The given triangles are congruent by :
because they have Two Angles and a side between them equal to the corresponding Angles and side of the another triangle.
