Answer:
23 or 19
Explanation:
15+8= 23
23-4= 19
i added 15 and 8 because if you were to flatten the triangle it would be next to the base, so i added it. I subtracted 4 because side C doesn't look like it is is about 23 ft. it could be 20 too.
i am not exactly sure. sorry if you get it wrong. I am so sorry if i got it wrong.