I need help please I have to finish this

Perimeter: 53cm Area: 90cm²

Step-by-step explanation:

For the perimeter, we just add all of the sides of triangle ABC. We have two of them, but we need the length of BC. Using Pythagorean Therom on triangle BCD, we get this length to be 13. So, 13+25+15= 53 cm.

For the area, we can take the area of the big triangle ADB and subtract the area of triagle BCD so that we are left with the area for triangle ABC. Using Area= .5 x base x height, we get that the area of the large triangle is 120cm² and the area of the small triangle is 30 cm², leaving the area of ABC to be 90 cm².

(Note: the formula for area of the triangle only works on triangles with a right angle or triangles were the height and base are perpendicula, so simply doing .5 x 15 x 12 will not work. However, .5 x 15 x 12 does work because it is perpendicular.)

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step-by-step explanation: